Fix a deprecation warning with newer Perl that breaks some tests.

--- a/tp/Texinfo/Parser.pm
+++ b/tp/Texinfo/Parser.pm
@@ -5438,12 +5438,12 @@
     }
   } elsif ($command eq 'clickstyle') {
     # REMACRO
-    if ($line =~ /^\s+@([[:alnum:]][[:alnum:]\-]*)({})?\s*/) {
+    if ($line =~ /^\s+@([[:alnum:]][[:alnum:]\-]*)(\{})?\s*/) {
       $args = ['@'.$1];
       $self->{'clickstyle'} = $1
         unless(_ignore_global_commands($self));
       $remaining = $line;
-      $remaining =~ s/^\s+@([[:alnum:]][[:alnum:]\-]*)({})?\s*(\@(c|comment)((\@|\s+).*)?)?//;
+      $remaining =~ s/^\s+@([[:alnum:]][[:alnum:]\-]*)(\{})?\s*(\@(c|comment)((\@|\s+).*)?)?//;
       $has_comment = 1 if (defined($4));
     } else {
       $self->line_error (sprintf($self->__(
lected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>refs</a><a class='active' href='/guix/log/gnu/packages/debug.scm'>log</a><a href='/guix/tree/gnu/packages/debug.scm?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>tree</a><a href='/guix/commit/gnu/packages/debug.scm?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>commit</a><a href='/guix/diff/gnu/packages/debug.scm?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/debug.scm'>
<input type='hidden' name='id' value='2dd1bfcb5800aad8f360c113cbd769019b5c9d84'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>root</a>/<a href='/guix/log/gnu?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>gnu</a>/<a href='/guix/log/gnu/packages?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>packages</a>/<a href='/guix/log/gnu/packages/debug.scm?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84'>debug.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/debug.scm?id=2dd1bfcb5800aad8f360c113cbd769019b5c9d84&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-05-24 02:34:08 -0400'>2018-05-24</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=9d10a63402e3c3dcda288b9370d04568dfa20ea6'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-05-23 13:58:40 +0200'>2018-05-23</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=6c7d0620cf1d893a9fa71a0d7f556314ef09531b'>gnu: Use "code" instead of "indent".</a><span class='msg-avail'>...</span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2018-04-30 04:03:54 -0400'>2018-04-30</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=3d5ad159b336a9903b31d0be7ae052dbc8d5bfcc'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-04-26 12:45:57 +0200'>2018-04-26</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=27b52c1f6aa036ec99691a5c76ecf697e09cd62f'>gnu: qemu: Build with Python 3 and SDL2 support.</a><span class='msg-avail'>...</span></td><td>Rutger Helling</td></tr>
<tr><td><span title='2018-03-14 17:37:20 +0100'>2018-03-14</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=8c72ed923d77ee55989965bb02628043799b9548'>Merge branch 'master' into core-updates</a></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2018-03-11 22:04:40 +0100'>2018-03-11</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=189be331acfda1c242a9c85fca8d2a0356742f48'>build-system/gnu: Add 'bootstrap' phase.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-03-07 15:37:11 +0100'>2018-03-07</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=7649e4269ef2107da5fbbb1e112f4be00338d0e9'>gnu: c-reduce: Use HTTPS home page.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-03-07 15:37:11 +0100'>2018-03-07</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=2b30af95416f37f8e371d59f6a7dd8607aea6e2a'>gnu: c-reduce: Update to 2.6.0.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-03-02 15:52:56 +0100'>2018-03-02</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=139ecdee8e592c515eea8cff4b918f0655196b4c'>gnu: delta: Remove redundant code.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-02-22 22:15:21 +0200'>2018-02-22</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=5c213d1bee60a7e2667feda9b8a2997624e5f447'>gnu: american-fuzzy-lop: Change custom qemu input.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-01-16 22:23:57 +0200'>2018-01-16</span></td><td><a href='/guix/commit/gnu/packages/debug.scm?id=7746af660524d7b26c46086116f4386f20050fdd'>gnu: american-fuzzy-lop: Update to 2.52b.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>