Bad antenna after flight or telemetry reset

[janekx]

Did found bad bug in reset of the Flight and Telemetry.
Taranis Plus B01
When reset flight or telemetry, the SWR value goes from 0 to 255 and back to 0, in this time OpenTX alert bad antenna.
This should not happend.

[projectkk2glider]

Confirmed from the sources:

• when telemetry is reset all values go to zero (including SWR)
• until XJT_VERSION_ID is recieved the IS_VALID_XJT_VERSION() is false
• if SWR packet comes and IS_VALID_XJT_VERSION() is still false, the SWR gets set to 0xFF.

[bsongis]

Confirmed. I can't remind why we set SWR to 0xFF when IS_VALID_XJT_VERSION() is false. Right now I would set it to 0x00

[bsongis]

I will mark this one as fixed once the whole SWR masking feature is ported to 'next'