Validation errors can prevent an agent from being disabled

[strugee]

STR:

1. Set up an agent.
2. Wait until that agent's validation rules are changed. In my case this appears to be when the Weather Agent's implementation was changed to DarkSky (I know this happened a long time ago - yes I have been ignoring NilClass exceptions for literally years 😅)
3. Go to the agent's details view (i.e. /agents/:id)
4. Click Actions > Disable agent > Yes

Expected result: the agent is disabled without question. In my case I wanted to disable it specifically to suppress the errored jobs clogging up my Jobs view (which now that I've seen the validation error, are presumably being caused by the agent having invalid configuration).

Actual result: 1 error prohibited this Agent from being saved: Location <scrubbed> is malformed. Location for Dark Sky must be in the format "-00.000,-00.00000". The number of decimal places does not matter.

I'm on git commit 68b759a3f0874507d1871cf5c4700950579818d9 which is obviously pretty old, but I also don't see any bug reports about this so I assume it's present in the latest version too. Will update soon just to be sure and report back.