[snappy] Set windowing backend to X11

[Luis de Bethencourt <luisbg src gnome org>]

commit 529445d6fc5da3ea6e5c81051248b9d4818a1224
Author: Balló György <ballogyor gmail com>
Date:   Wed Apr 15 15:46:14 2015 +0200

    Set windowing backend to X11
    
    This required to work with Clutter 1.22.

 src/snappy.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/snappy.c b/src/snappy.c
index 6054c88..c2bb2d0 100644
--- a/src/snappy.c
+++ b/src/snappy.c
@@ -179,6 +179,7 @@ main (int argc, char *argv[])
 
   context = g_option_context_new ("<media file> - Play movie files");
 
+  clutter_set_windowing_backend (CLUTTER_WINDOWING_X11);
   ci_err = gtk_clutter_init (&argc, &argv);
   if (ci_err != CLUTTER_INIT_SUCCESS)
     goto quit;