On ADIF import, ask the user if no station callsign is detected

[ea4k]

In the past KLog ask twrite the callsign when was not in the adif

If no station callsign is detectad on adif import, KLog should ask the user if it should add a Station Callsign or not.

[ea5wa]

Not only when importing, when entering manually a QSO station callsign is not fulfilled by KLog