add USE_WEBSOCKET to PreporcessorDefinitions
add USE_WEBSOCKET to PreporcessorDefinitions

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