NewPipe legacy: Link to F-Droid → 404

[WebworkrNet]

https://newpipe.net:
Link (button) to https://f-droid.org/repo/org.schabi.newpipelegacy_120.apk turns to a 404.

[TobiGr]

the old problem: new version released, but F-Droid is slow with updating.
@TheAssassin We should parse F-Droid's index.json and not the metadata files.