[gnome-user-share] Add missing string.h include

[Bastien Nocera <hadess src gnome org>]

commit e53cb4ddde2ed09433862b3f93d6885075e824e7
Author: Bastien Nocera <hadess hadess net>
Date:   Fri Jan 6 17:14:26 2012 +0000

    Add missing string.h include
    
    https://bugzilla.gnome.org/show_bug.cgi?id=664929

 src/user_share-common.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/user_share-common.c b/src/user_share-common.c
index 31389eb..6821d07 100644
--- a/src/user_share-common.c
+++ b/src/user_share-common.c
@@ -22,6 +22,8 @@
  *
  */
 
+#include <string.h>
+
 #include "user_share-common.h"
 
 static char *