configitems: do not directly match generic items
Before this changesets, a literal '.*:foo$' config would match a registered
'.*:foo$' generic. This is wrong since generic should be matched through
regular exception only. This changeset fixes this problem.
Thanks for to Yuya Nishihara for spotting the issue.
http://example.com/no/anchor, branches: (None, [])
http://example.com/an/anchor, branches: ('foo', [])
http://example.com/no/anchor/branches, branches: (None, ['foo'])
http://example.com/an/anchor/branches, branches: ('bar', ['foo'])
http://example.com/an/anchor/branches-None, branches: ('foo', [])
http://example.com/, branches: (None, [])
http://example.com/, branches: (None, [])
http://example.com/, branches: ('foo', [])