Fix GitHub user page regex
Fix GitHub user page regex

beetbox/beets,sampsyo/beets,ibmibmibm/beets,beetbox/beets,shamangeorge/beets,ibmibmibm/beets,beetbox/beets,sampsyo/beets,sampsyo/beets,beetbox/beets,ibmibmibm/beets,ibmibmibm/beets,shamangeorge/beets,shamangeorge/beets,sampsyo/beets,shamangeorge/beets