This fixes a regression introduced in 1.8.0 where libssh2 fails to build
with the gcrypt backend.

Upstream bug URL:

https://github.com/libssh2/libssh2/issues/150

Patch copied from upstream source repository:

https://github.com/libssh2/libssh2/commit/ced924b78a40126606797ef57a74066eb3b4b83f

From ced924b78a40126606797ef57a74066eb3b4b83f Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <siarheit@google.com>
Date: Mon, 31 Oct 2016 09:04:33 +0000
Subject: [PATCH] acinclude.m4: fix ./configure --with-libgcrypt

diff --git a/acinclude.m4 b/acinclude.m4
index 734ef07..c78260c 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -412,9 +412,9 @@ AC_DEFUN([LIBSSH2_CHECKFOR_GCRYPT], [
 
   old_LDFLAGS=$LDFLAGS
   old_CFLAGS=$CFLAGS
-  if test -n "$use_libgcrypt" && test "$use_libgcrypt" != "no"; then
-    LDFLAGS="$LDFLAGS -L$use_libgcrypt/lib"
-    CFLAGS="$CFLAGS -I$use_libgcrypt/include"
+  if test -n "$with_libgcrypt_prefix" && test "$use_libgcrypt" != "no"; then
+    LDFLAGS="$LDFLAGS -L$with_libgcrypt_prefix/lib"
+    CFLAGS="$CFLAGS -I$with_libgcrypt_prefix/include"
   fi
   AC_LIB_HAVE_LINKFLAGS([gcrypt], [], [
     #include <gcrypt.h>
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<div class='path'>path: <a href='/guix/log/?id=9c072f820e05736e4e6536192d0af213e0277408'>root</a>/<a href='/guix/log/gnu?id=9c072f820e05736e4e6536192d0af213e0277408'>gnu</a>/<a href='/guix/log/gnu/packages?id=9c072f820e05736e4e6536192d0af213e0277408'>packages</a>/<a href='/guix/log/gnu/packages/image-processing.scm?id=9c072f820e05736e4e6536192d0af213e0277408'>image-processing.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/image-processing.scm?id=9c072f820e05736e4e6536192d0af213e0277408&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-05-17 01:00:50 -0400'>2018-05-17</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=539bf8f2c071b53834829259bb3fabf0390c5dc6'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-05-14 23:01:36 +0200'>2018-05-14</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=5834e4b70aef727d591c271ce3141ed23753377e'>gnu: opencv: Ignore CVEs.</a><span class='msg-avail'>...</span></td><td>Björn Höfling</td></tr>
<tr><td><span title='2018-05-09 23:50:41 +0200'>2018-05-09</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=62834314434323e5250f9d99b35d523ca216b540'>gnu: Add opencv.</a><span class='msg-avail'>...</span></td><td>Björn Höfling</td></tr>
<tr><td><span title='2018-03-18 00:16:52 +0100'>2018-03-18</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=6a6db57f843e07f6b37508f0bc1c2d4c919debe0'>gnu: Switch from xproto to xorgproto.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2018-01-23 17:01:07 -0500'>2018-01-23</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=a102d359a68ce7219a1880e47dd6f9332cbbce3a'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-01-21 20:40:28 +0100'>2018-01-21</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=11861d2bf01ca7da3a8fcdd91a8606fd17ef9421'>gnu: mia: Update to 2.4.6.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-12-19 19:52:01 +0200'>2017-12-19</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=677bc34d5b75d4c9a8020f9d0f917c3ca2fb3dc6'>gnu: Remove redundant cmake libdir configure flags.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2017-06-03 18:19:07 +0200'>2017-06-03</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=98d6cdda37721ca950732aec272f6e004c402959'>gnu: Remove old vtk module dependence in image-processing.scm.</a><span class='msg-avail'>...</span></td><td>Julien Lepiller</td></tr>
<tr><td><span title='2017-06-02 18:47:06 +0200'>2017-06-02</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=fb226b43511671bee3463a02eea9e041d2610fef'>gnu: Move vtk to image-processing.scm.</a><span class='msg-avail'>...</span></td><td>John Darrington</td></tr>
<tr><td><span title='2017-05-15 21:34:09 +0200'>2017-05-15</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=cdb2a21160a195f63c33955d8b9b9034e11dae46'>gnu: Add mia.</a><span class='msg-avail'>...</span></td><td>John Darrington</td></tr>
<tr><td><span title='2017-05-15 21:22:06 +0200'>2017-05-15</span></td><td><a href='/guix/commit/gnu/packages/image-processing.scm?id=504c285d1092c9b7a2ef25c7a436da02bef70dc2'>gnu: Add dcmtk.</a><span class='msg-avail'>...</span></td><td>John Darrington</td></tr>