Update v3.py - Fix error in _get_array_outer_type

[mmangione]

The except clause of _get_array_outer_type can return field_info.annotation as a list, so the args element is not valid. Check for this type and return the raw element.

[tyzhnenko]

Hey @mmangione.

Would you happen to have an example of when the error appears?

[mmangione]

Yep. This is a follow-up from my issue below.

#492

We aren't doing anything out-of-the-ordinary. We use OpenAPI to build docs for some of our routes, as specified in the dev docs. We were using the latest version of BlackSheep 1.x when we originally built those docs.

[mmangione]

I made a mistake in my PR. I need to update it. Closing this one.