D6499: phabricator: make `hg debugcallconduit` work outside a hg repo

[Yuya Nishihara]

> - at vcrcommand(b'debugcallconduit', [], _(b'METHOD'))
> -def debugcallconduit(ui, repo, name):
> + at vcrcommand(b'debugcallconduit', [], _(b'METHOD'), norepo=True)
> +def debugcallconduit(ui, name):

Maybe optionalrepo to load repo/.hg/hgrc?