multimedia/gpodder: update to 3.10.8
- update to latest 3.10.8 version and switch to github
- follow upstream development and switch the port to py3/gtk3
- adjust options and dependencies accordingly
- comment off eyed3 dependency, because version in ports in not py3-compatible
- remove patch, merged upstream; update homepage URL
- change DATADIR in plist with relative patch, because gpodder doesn't support changing it's files location