panic because of statping_emailer record in notifications table

[fuerst]

Upgrading from v0.90.78 to v0.91.0 I got a panic: runtime error: invalid memory address or nil pointer dereference error. Deleting the statping_emailer record in the notifications table fixed it. I'm using a Sqlite database.

The solution was reported earlier here:
#124 (comment)

Thanks for maintaining statping-ng anyway!

[jemand771]

uh-oh, regression from #83

I think we can add a db migration to do this automatically in a future release. Thanks for bumping this again 👀