x11/xfce4-terminal: Fix "unsafe paste dialog" functionality

Import patch from upstream to fix a bug in the latest relase that
prevents the "unsafe paste dialog" feature from working.

PR:		277276
btained from:	https://gitlab.xfce.org/apps/xfce4-terminal/-/commit/177fda86451cdeaaea8ed409e6d711b670699a97