backends: push missing error trap

This went MIA in commit 390314adfb, and causes asserts when
trying to pop a non-existent error trap a bit later.

Closes: #294

src/backends/x11/meta-input-settings-x11.c

@@ -783,6 +783,9 @@ meta_input_settings_x11_set_stylus_button_map (MetaInputSettings          *setti
 
   /* Grab the puke bucket! */
   xdev = device_ensure_xdevice (device);
+
+  meta_x11_error_trap_push (display->x11_display);
+
   if (xdev)
     {
       guchar map[8] = {

src/x11/window-props.c

@@ -1729,8 +1729,7 @@ reload_gtk_hide_titlebar_when_maximized (MetaWindow    *window,
 
   window->hide_titlebar_when_maximized = requested_value;
 
-  if (META_WINDOW_MAXIMIZED (window) ||
-      META_WINDOW_TILED_SIDE_BY_SIDE (window))
+  if (META_WINDOW_MAXIMIZED (window))
     {
       meta_window_queue (window, META_QUEUE_MOVE_RESIZE);
       meta_window_frame_size_changed (window);