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

test/integration/client.cpp

@@ -25,6 +25,7 @@
 #include <boost/system/error_code.hpp>
 
 #include <async_mqtt5.hpp>
+#include <async_mqtt5/websocket.hpp>
 
 namespace async_mqtt5 {