Only show instances with api enabled when redirecting an api link

[ChunkyProgrammer]

If redirecting an api url then instances that have the api disabled are filtered out.

An example of this being useful is the api documentation, there is a link to redirect an api url here: https://docs.invidious.io/api/#fields (which will redirect to this url: https://redirect.invidious.io/api/v1/videos/aqz-KE-bpKQ?fields=videoId,title,description&pretty=1 )

Before this PR, yewtu.be which has the api disabled would be shown when redirecting api urls. After this PR, yewtu.be is filtered out as well as any other future instances that decide to disable the api.

Test cases: Redirect an api url: yewtu.be is not shown

Redirect a video url: yewtu.be is shown

[unixfox]

Please write a description and give examples please.

[ChunkyProgrammer]

Please write a description and give examples please.

Oups, sorry. I added a description