cad/zcad: mark qt5 flavor BROKEN

(3104) Compiling glqtcontext.pas
/wrkdirs/usr/ports/cad/zcad/work-qt5/zcad-8b8a693/cad_source/glqtcontext.pas(30,23) Fatal: (10022) Can't find unit qlclopenglwidget used by GLQTContext
Fatal: (1018) Compilation aborted

Reported by:	pkg-fallout

cad/zcad/Makefile

@@ -56,6 +56,8 @@ OPTIONS_DEFINE=		DOCS
 
 .if ${FLAVOR:Ugtk2:Mgtk2}
 MAKE_ENV+=	GUI=gtk2
+.elif ${FLAVOR:Ugtk2:Mqt5}
+BROKEN=		fails to build
 .endif
 
 post-patch: