Fixed subscription handler logic.

Subscription.cpp

@@ -28,7 +28,7 @@ namespace core {
       if (handler)
         handler->onSubscribe(session, this);
       else
-        onSubscribe(session, this);
+        onSubscribe(session);
 
       subscribers.push_back(&session);
       return 1;
@@ -62,7 +62,7 @@ namespace core {
       return (std::find(subscribers.begin(), subscribers.end(), &session) != subscribers.end());
    }
 
-   int Subscription::onSubscribe(TCPSession &session, Subscription *subscription) {
+   int Subscription::onSubscribe(TCPSession &session) {
       return 0;
    }