Fix RecordUnknown behaviors

[taclane]

The monitoring state UNKNOWN_TG is currently unused, and appears to exist to flag calls that will not be recorded if "recordUnknown": false is set in a system config and the talkgroup cannot be found in the .csv.

The setting hideUnknownTalkgroups currently does nothing as the only use in trunk-recorder is commented out. Per the documents, the expected logging behavior should be:

Key	Required	Default Value	Type	Description
hideUnknownTalkgroups		false	true / false	Hide unknown talkgroups log entries

This small patch will flag a monitoring state when unknown talkgroups will not be recorded, and restore messages like the below unless otherwise configured:

(info)   [name]  6C  TG: 12345 (  -)  Freq: 774.606250 MHz  Not Recording: TG not in Talkgroup File

[robotastic]

Good catch! I am not quite sure why that got commented out