compute timeout based on fake sample count not real life one

src/switch_core_session.c

@@ -1550,7 +1550,7 @@ SWITCH_DECLARE(void) switch_core_session_enable_heartbeat(switch_core_session_t
 		return;
 	}
 
-	session->read_frame_count = (session->read_impl.actual_samples_per_second / session->read_impl.samples_per_packet) * seconds;
+	session->read_frame_count = (session->read_impl.samples_per_second / session->read_impl.samples_per_packet) * seconds;
 
 
 	switch_core_session_unsched_heartbeat(session);