RS41-SGM Unencrypted Telemetry

[darksidelemm]

Just a FYI that @rs1729 added support for decoding of RS41-SGM unencrypted telemetry in his rs41mod decoder here: https://github.com/rs1729/RS/blob/master/demod/mod/rs41mod.c#L1265

We added support into radiosonde_auto_rx, and have been able to track and recover quite a few RS41-SGM sondes that were launched near Adelaide.

[bazjo]

the modified frame structure was discussed here https://www.fingers-welt.de/phpBB/viewtopic.php?f=14&t=43&start=2950

I have all the data I need and will add this once i'll come around to it