remove color codes from the message

Otherwise you get stuff like this:

    18:44:22 <  SpacenearUS> lz1dev: Telemetry: Main 1.516 V Aux 0 V Temp 4.5 C Sat 11 # Alt 6310 ft
    18:44:49 < theRealSIbot> In real units: 106310 ft = 32 km