I get some messages starting $$GPGLL and $$GPGSV rather than $GPGLL and $GPGSV

[murkle]

Suggestion to add to parseNMEAMessage()

	// I get some messages starting $$GPGLL and $$GPGSV rather than $GPGLL and $GPGSV
	if (data.startsWith("$$")) {
		data = data.substring(1);
	}