Bug in Message Creation Fixed

Last night a noticed a couple of users trying to send out APRS messages that were failing. The failure was because the callsigns were typed in lower case and were not being converted to uppercase before they were stored for transmission. The server backend is coded to be very picky about what it sends out so it rejected the messages. I've fixed the bug and callsigns can be given in upper or lower case from the APRS messaging window and they will be accepted and transmitted correctly.