PICARD-636: use a better example VA release for tag preview

Use track 2.5 from http://musicbrainz.org/release/4b50c71e-0a07-46ac-82e4-cb85dc0c9bdd as suggested by KRSCuan.

http://tickets.musicbrainz.org/browse/PICARD-636
`~multiartist` should be added as well.