time_zone2 setting is now populated from GTTMZ and GTINF reports for GV58CEU, GV310LAU, GV355CEU, GV305CEU, GL50B, GL50B Lite, GV50, GV57CEU, GV30CEU, GV30CAU devices. This enables automatic timezone-based timestamp correction (local time → UTC) for these devices without requiring explicit AT+GTRTO setting reads.
Note: Devices configured with a non-zero timezone offset may see corrected timestamp values in GTTMZ and GTINF messages after this update. Previously, timestamps from these reports were stored as-is (local time); now they are properly converted to UTC. Most devices use UTC+0 and are unaffected.
