glib-compile-schemas: Fix a minor memory leak

Signed-off-by: Philip Withnall <withnall@endlessm.com>
diff --git a/gio/glib-compile-schemas.c b/gio/glib-compile-schemas.c
index d4340d4..5e1bebb 100644
--- a/gio/glib-compile-schemas.c
+++ b/gio/glib-compile-schemas.c
@@ -2112,6 +2112,7 @@
         }
 
       g_strfreev (groups);
+      g_key_file_free (key_file);
     }
 
   return TRUE;