Fix building of Shishi with libgcrypt 1.6 and later.

Patch copied from Debian:

https://anonscm.debian.org/cgit/collab-maint/shishi.git/tree/debian/patches/fix_gcrypt_detection.diff?id=948301ae648a542a408da250755aeed58a6e3542

Description: Fix autoconf gnutls detection to also accept gcrypt 1.6.
Author: Andreas Metzler <ametzler@debian.org>
Bug-Debian: http://bugs.debian.org/753150
Origin: vendor
Forwarded: no
Last-Update: 2014-07-18

--- shishi-1.0.2.orig/gl/m4/gc.m4
+++ shishi-1.0.2/gl/m4/gc.m4
@@ -12,10 +12,12 @@ AC_DEFUN([gl_GC],
   if test "$libgcrypt" != no; then
     AC_LIB_HAVE_LINKFLAGS([gcrypt], [gpg-error], [
 #include <gcrypt.h>
-/* GCRY_MODULE_ID_USER was added in 1.4.4 and gc-libgcrypt.c
-   will fail on startup if we don't have 1.4.4 or later, so
-   test for it early. */
-#if !defined GCRY_MODULE_ID_USER
+/* gc-libgcrypt.c will fail on startup if we don't have libgcrypt 1.4.4 or
+   later, test for it early. by checking for either
+   - GCRY_MODULE_ID_USER which was added in 1.4.4 and dropped in 1.6 or
+   - GCRYPT_VERSION_NUMBER which was added in 1.6.
+   */
+#if !defined GCRY_MODULE_ID_USER && !defined GCRYPT_VERSION_NUMBER
 error too old libgcrypt
 #endif
 ])
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<div class='path'>path: <a href='/guix/log/?id=0b23c3e38407a5d930aae70754fe40a665bb11b2'>root</a>/<a href='/guix/log/gnu?id=0b23c3e38407a5d930aae70754fe40a665bb11b2'>gnu</a>/<a href='/guix/log/gnu/tests?id=0b23c3e38407a5d930aae70754fe40a665bb11b2'>tests</a>/<a href='/guix/log/gnu/tests/vnc.scm?id=0b23c3e38407a5d930aae70754fe40a665bb11b2'>vnc.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/tests/vnc.scm?id=0b23c3e38407a5d930aae70754fe40a665bb11b2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-07-19 10:38:15 -0400'>2023-07-19</span></td><td><a href='/guix/commit/gnu/tests/vnc.scm?id=1edbadc6b49adda050a87057e6501c961888d7bb'>tests: xvnc: Fix 'gdm auto-suspend is disabled' test.</a><span class='msg-avail'>...<span class='msg-tooltip'>This failure is another collateral from commit a09c7da ("tests: Fork and exec
a new Guile for the marionette REPL."), which isolated the marionette
evaluation environment from that of the host.

* gnu/tests/vnc.scm (run-xvnc-test): Move the (guix build utils) import to...
["gdm auto-suspend is disabled"]: ... inside the marionette-eval of this
test.  Complete comment.

Reported-by: Bruno Victal &lt;mirai@makinata.eu&gt;
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2023-07-19 10:38:15 -0400'>2023-07-19</span></td><td><a href='/guix/commit/gnu/tests/vnc.scm?id=95424292993551854fb7373cef997fd39340ea4b'>tests: xvnc: Group up GDM test and use GNU Ocrad instead of Tesseract.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/tests/vnc.scm (run-xvnc-test): Group up GDM test.  Use GNU Ocrad.

Signed-off-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;
Modified-by: Maxim Cournoyer &lt;maxim.cournoyer@gmail.com&gt;
</span></span></td><td>Bruno Victal</td></tr>