cmdserver: take repo.baseui as our ui
The ui passed to server() is really repo.ui, that is it contains its local
configuration as well.
When running commands that use a different repo than the servers cached repo,
we don't want to use that ui as the baseui for the new repo.
$ echo '[Section]' >> $HGRCPATH
$ echo 'KeY = Case Sensitive' >> $HGRCPATH
$ echo 'key = lower case' >> $HGRCPATH
$ hg showconfig Section
Section.KeY=Case Sensitive
Section.key=lower case