search: Fix memory leak

g_variant_get_strv() returns newly allocated memory.
This should be freed when no longer required.

https://bugzilla.gnome.org/show_bug.cgi?id=782048

panels/search/cc-search-panel.c

@@ -406,6 +406,7 @@ switch_settings_mapping_get_generic (GValue *value,
         }
     }
 
+  g_free (apps);
   g_value_set_boolean (value, !!default_enabled != !!found);
 
   return TRUE;