expect seqNo in payload and not in port

include/timesync.h

@@ -7,7 +7,7 @@
 #include "timekeeper.h"
 
 //#define TIME_SYNC_TRIGGER 100 // threshold for time sync [milliseconds]
-#define TIME_SYNC_FRAME_LENGTH 0x05 // timeserver answer frame length [bytes]
+#define TIME_SYNC_FRAME_LENGTH 0x06 // timeserver answer frame length [bytes]
 #define TIME_SYNC_FIXUP 4 // calibration to fixup processing time [milliseconds]
 
 void timesync_init(void);