serve: respect settings from .hg/hgrc
create_server was looking only at the root ui object, ignoring any
settings from .hg/hgrc. To keep respecting command-line arguments,
commands.serve must also call repo.ui.setconfig.
adding a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b
pushing to ../a
abort: could not lock repository ../a: Permission denied