Invalid dates in relays_published and bridges_published fields

There's a problem with dates in Onionoo's output:

{"relays_published":"9014-04-14 03:00:00",
"relays":[],
"bridges_published":"14840-04-28 10:37:04",
"bridges":[]}

Apparently this bug was introduced in the latest commit series from today. I still had the previous .war file around, and deploying that seemed to fix the issue. I don't know yet what the bug is.