sendI2cCommand writes the wrong character if lenght =n*i2cTransactionSize + 1

The line
https://github.com/sparkfun/SparkFun_u-blox_GNSS_Arduino_Library/blob/9f301c815a3910e9d3b9b63914d22e77783f8858/src/SparkFun_u-blox_GNSS_Arduino_Library.cpp#L2952 

Seems to be a intended to work with ```*outgoingUBX->payload += len;``` which moves the payload pointer, but is now commented. I think it should be ```_i2cPort->write(outgoingUBX->payload[startSpot], 1);```