wsi/x11: Use get_screen_resources_current in wsi_x11_detect_xwayland

get_screen_resources may trigger an active probe of display connections in the X server, which may take significant time and/or result in log file spam.

Fixes: b5268d53 "wsi/x11: Detect Xwayland" Reported-by: Sylvain Bertrand sylvain.bertrand@legeek.net