Fix warning for unused function in gcc if compiled WITH_WEBSOCKET but without WITH_LUA
Fix warning for unused function in gcc if compiled WITH_WEBSOCKET but without WITH_LUA

See also issue #104

GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver,GerHobbelt/civet-webserver