Remove Beast dependency from connect_op.hpp

Summary: resolves T15243

Reviewers: ivica

Reviewed By: ivica

Subscribers: iljazovic, miljen

Maniphest Tasks: T15243

Differential Revision: https://repo.mireo.local/D32561

example/hello_world_over_websocket_tcp.cpp

@@ -15,6 +15,7 @@
 #include <boost/beast/websocket.hpp>
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp> // WebSocket traits
 
 int main() {
 	boost::asio::io_context ioc;