Autogain Run 1 Immediate Completion

[MNTech68]

The autogain script appears to need an adjustment to the "first time run".

When run, the script starts, but almost immediately it finishes run 1, even though the requisite time ($READSB_AUTOGAIN_INITIAL_INTERVAL) has not passed.

Here are the logs and time stamps:
dump978 | [2024-09-22 09:59:09.235][autogain] [INFO] Autogain initialization started. We'll collect data every 900 secs for 540 minutes to do an initial gain assessment
dump978 | [2024-09-22 09:59:13.302][autogain] [INFO] Data collection is complete for initialization run 1 of 36 (total_msg_count;strong_msg_count;%strong=0;0;na)