Ignore X11 errors caused by ReparentWindow / ChangeProperty on already destroyed windows

These errors can happen because a DestroyWindow request by a client will
trigger an UnmapNotify, then a DestroyNotify. We cannot distinguish this
UnmapNotify from an UnmapNotify not followed by a DestroyNotify, so we just try
to send the ReparentWindow / ChangeProperty and ignore the errors, if any.

src/xcb.c

@@ -328,7 +328,7 @@ void xcb_set_window_rect(xcb_connection_t *conn, xcb_window_t window, Rect r) {
                          XCB_CONFIG_WINDOW_HEIGHT,
                          &(r.x));
     /* ignore events which are generated because we configured a window */
-    add_ignore_event(cookie.sequence, 0);
+    add_ignore_event(cookie.sequence, -1);
 }
 
 /*