MAVLink app: Adjust stack size of receiver thread

src/modules/mavlink/mavlink_receiver.cpp

@@ -1548,7 +1548,7 @@ MavlinkReceiver::receive_start(Mavlink *parent)
 	param.sched_priority = SCHED_PRIORITY_MAX - 80;
 	(void)pthread_attr_setschedparam(&receiveloop_attr, &param);
 
-	pthread_attr_setstacksize(&receiveloop_attr, 2100);
+	pthread_attr_setstacksize(&receiveloop_attr, 1800);
 	pthread_t thread;
 	pthread_create(&thread, &receiveloop_attr, MavlinkReceiver::start_helper, (void *)parent);