By default 'mutt' embeds configure flags and the output of 'gcc -v',
which contains the store file name of Bash and GCC.  This patch makes
sure we don't embed a reference to these in 'mutt'.

--- mutt-1.5.23/txt2c.sh	2015-06-26 22:56:56.500731643 +0200
+++ mutt-1.5.23/txt2c.sh	2015-06-26 22:57:26.664583900 +0200
@@ -21,6 +21,8 @@ txt2c_fallback () {
 	echo ";"
 }
 
+echo "unsigned char $1[] = \"value of '$1' not kept\";"
+exit 0
 ./txt2c test </dev/null >/dev/null 2>&1 &&
 ./txt2c "$1" ||
 txt2c_fallback "$1"

ex</a> : <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>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=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>refs</a><a class='active' href='/guix/log/gnu/system/pam.scm'>log</a><a href='/guix/tree/gnu/system/pam.scm?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>tree</a><a href='/guix/commit/gnu/system/pam.scm?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>commit</a><a href='/guix/diff/gnu/system/pam.scm?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/system/pam.scm'>
<input type='hidden' name='id' value='4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'/><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=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>root</a>/<a href='/guix/log/gnu?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>gnu</a>/<a href='/guix/log/gnu/system?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>system</a>/<a href='/guix/log/gnu/system/pam.scm?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6'>pam.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/system/pam.scm?id=4ea3215d8f18453e6b8ff0a46654e52b5741c3e6&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-08-17 01:10:25 +0300'>2021-08-17</span></td><td><a href='/guix/commit/gnu/system/pam.scm?id=b948ab8b56ac238e7a774625b8f971d28aee6055'>services: slim: Add pam-gnupg support.</a><span class='msg-avail'>...</span></td><td>Oleg Pykhalov</td></tr>
<tr><td><span title='2020-05-08 16:30:50 +0200'>2020-05-08</span></td><td><a href='/guix/commit/gnu/system/pam.scm?id=dd0804c67e99914eecc471fdb92f4220425a1cbc'>services: Add descriptions.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>