Fix: RBAC handle error no resolver found

[gamab]

What this PR does / why we need it:

During the backport #54692, we forgot to catch the scope resolver error. This fixes the warning log problem some users have been facing.

Which issue(s) this PR fixes:

Fixes #55654

Special notes for your reviewer:

[grafanabot]

Drone build failed: https://drone.grafana.net/grafana/grafana-enterprise/34912

[vtorosyan]

Do we need to backport already, since the 9.2 is branched off I believe?

[gamab]

This is going to 9.1.x, it fixes a backport we previously did. 9.2.x is already working correctly 👍

[iridos]

We are getting a steady stream of about 400 messages per hour like [1] since upgrading to grafana 9.1.5 on 2022-09-14 - am I mistaken or will this fix our logspam?
Our messages differ from the one in #55654 by being errors, not warnings (and having a different msg part as well as a different logger etc)

[1] logger=context traceID=00000000000000000000000000000000 userId=0 orgId=1 uname= t=2022-09-29T11:31:43.653345729+02:00 level=error msg="Error from access control system" error="no resolver found"

[gamab]

@iridos yes, this should fix it. 🙂

[iridos]

Great 👍