When a new network is added to the list of checked networks, do not fill in gaps in checks
The current behaviour is to fill up the checks from the beginning of the use of waveqc.
But the retry_failing_checks routine will try to rerun those checks. It could be a massive amount of checks that could :
- take a few hours
- overlap between two retry_failing_checks routine that run every hour
- crash the server by filling up the disk
Find a way to solve this situation