Compare connections by object id

(cherry picked from commit 02535e7f17)

core/object.cpp

@@ -356,7 +356,7 @@ bool Object::Connection::operator<(const Connection &p_conn) const {
 				return method < p_conn.method;
 			} else {
 
-				return target < p_conn.target;
+				return target->get_instance_id() < p_conn.target->get_instance_id();
 			}
 		} else
 			return signal < p_conn.signal;