fixed INS when no GPS fix

src/kernel/gps/INS.hx

@@ -69,8 +69,9 @@ class INS {
 	}
 
 	private static function move(dir:Null<Pos3>) {
-		Log.debug('INS move: $dir');
 		var pos = GPS.getPosition();
+		if (pos == null || dir == null)
+			return;
 		var newPos = pos + dir;
 		GPS.setINSPosition(newPos);
 	}