[feature] queued items are not kept through restarts

[dgtlmoon]

When the application restarts, the queued items are no longer kept, it will empty the "recheck queue" and generate new queued items according to the time between recheck schedule

This can be solved with #2735

on the hosted version, it will restart from time to time depending on memory usage etc

[dgtlmoon]

A really fool proof and reliable way would be to create a lockfile for each UUID that is in the queue rather than managing a DB