Changes:
    - B4Log.mdb adif import now imports FT4, MSK144 & QRA64 QSOs.
       Note: The B4Log.mdb file is only used when there is no enabled logger.

  Fixes:
    - ADIF Logging, import process not importing FT4 QSOs recorded as MODE=MFSK
       + SUBMODE=FT4. QSOs recorded as MODE=FT4 were imported correctly.
    - Special event callsigns with a single leading alpha character,
       like "R2019CG" not passing validation causing lack of alerts and an
       inability to add to the "Wanted Callsign" list.