[gcr] egg: Fix use of libgcrypt GCRY_THREAD_OPTION_PTHREAD_IMPL

[Stefan Walter <stefw src gnome org>]

commit 2a7183aa9828a9ad69bf815d81068ac0692b4d05
Author: Stef Walter <stefw gnome org>
Date:   Tue Sep 9 14:49:18 2014 +0200

    egg: Fix use of libgcrypt GCRY_THREAD_OPTION_PTHREAD_IMPL
    
    On certain libgcrypt versions (like 1.5.0) we need to include
    errno.h or compilation fails:
    
    ../egg/egg-libgcrypt.c:54:1: error: 'ENOMEM' undeclared (first use in
    this function)

 egg/egg-libgcrypt.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/egg/egg-libgcrypt.c b/egg/egg-libgcrypt.c
index e9a28b0..a833a9d 100644
--- a/egg/egg-libgcrypt.c
+++ b/egg/egg-libgcrypt.c
@@ -26,6 +26,8 @@
 
 #include <gcrypt.h>
 
+#include <errno.h>
+
 EGG_SECURE_DECLARE (libgcrypt);
 
 static void