[LyX/master] Add xcb lib if x11extras is detected

[Enrico Forestieri]

commit fe64db4b70b6bed8df17689e2ad9126076387f9d
Author: Enrico Forestieri <forenr at lyx.org>
Date:   Mon Jun 17 21:57:24 2024 +0200

    Add xcb lib if x11extras is detected
    
    In this case we use directly some xcb api outside of the Qt framework
    and hence we have to add the xcb library by ourselves.
---
 config/qt.m4 | 1 +
 1 file changed, 1 insertion(+)

diff --git a/config/qt.m4 b/config/qt.m4
index f947ae042d..14ec4e3f9f 100644
--- a/config/qt.m4
+++ b/config/qt.m4
@@ -464,6 +464,7 @@ EOF4
 		    fi
 		    QT5_X11_EXTRAS=`cd $lyx_test_qt_dir; make -s -f $lyx_test_qt_mak DEFINES | grep QT_X11EXTRAS_LIB`
 		    if test -n "$QT5_X11_EXTRAS"; then
+			QT_LIB="$QT_LIB -lxcb"
 			AC_DEFINE(HAVE_QT5_X11_EXTRAS, 1,
 				[Define if you have the Qt5X11Extras module])
 		    fi