change Voyager crashes into info

[juliangruber]

There's nothing that operators can do about these crashes. This PR changes the activity type into "Info"

[bajtos]

TBH, this feels very hacky to me. I prefer to handle these crashes in such a way that no activity logs are created. However, that requires quite a bit of work, starting in Zinnia. In this light, it's best to land this fix as a quick stop-gap solution.

[bajtos]

Created a Zinnia feature request here:

• Allow modules to handle uncaught errors/unhandled rejections zinnia#518

[juliangruber]

I very much agree!