Fixes#6514
## What changed?
I fixed a bug in our sql `DBHandle` that could cause us to never
reconnect to the database when an issue occurs.
## Why?
We should only update the last refresh time when we actually refresh. As
written we always update the last refresh time even when we don't
refresh.
If _every_ attempt to reconnect happens within
`sessionRefreshMinInterval` of the last attempt, the server will _never_
actually reconnect as it will just keep bumping the last refresh...
## How did you test it?
Existing tests
## Potential risks
None
## Documentation
No changes
## Is hotfix candidate?
Absolutely (cc @yiminc)
