qt4: enable QtXMLPatterns by default

qt/qt4/qt4.conf

@@ -99,6 +99,9 @@ var_append confopt ' ' "-nomake examples"
 [ "$SDECFG_PKG_QT4_EXCEPTION_STL" = "0" ] &&
 	var_append confopt " " "-no-exceptions -no-stl"
 
+# enable QtXmlPatterns by default
+var_append confopt ' ' "-xmlpatterns"
+
 # Add database support for all installed databases.
 tuples="mysql:mysql postgresql:psql sqlite:sqlite sqlite2:sqlite2"
 for tuple in $tuples; do