Protect definition of _GNU_SOURCE.

I was getting a duplicate definition of this from somewhere, so
getting compiler warnings without this protection.

diff --git a/notmuch-private.h b/notmuch-private.h
index 449aff7143e14023ee0b97c9a27824aceeb8b52d..a8ec8ebeee1371e9a5522669a1515be2394ae6d6 100644 (file)
--- a/notmuch-private.h
+++ b/notmuch-private.h
@@ -23,7 +23,9 @@
 
 #include "notmuch.h"
 
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE /* For getline */
+#endif
 
 #include <stdio.h>
 #include <stdlib.h>