Raise contact limit for D868/878 (fixes #50).

[fmarier]

Fixes #50.

The callsign limits were raised in firmware 1.35/2.35 for the AnyTone D868UV:

V1.35 and V2.35 Improvements (dated 2019-6-20) 3. Increase the digital contact to 200,000 contacts.

and in firmware 1.13 for the AnyTone D878UV:

D878UV firmware update V1.13 (dated 2019-6-8) 1.Increased to 200,000 digital contacts.

Thanks to @Eszartek for suggesting these changes in https://github.com/sergev/dmrconfig/issues/50#issuecomment-612654361.