www: repolist: support globbing in URL
    
    This can make it easier to find deeply-nested repositories on my
    mirror of git.kernel.org.  It's not perfect, since projects like
    Linux use several completely different basenames (e.g. linux.git
    vs vfs.git vs net.git), but it can still help find significant
    matches further up a tree.
    
    I don't expect glob characters to conflict with actual git
    repositories used by reasonable people, but direct (non-glob)
    hits are still tried first.