remoteui: copy http_proxy settings
http_proxy settings of current repo's .hg/hgrc should be available
on remoteui, so that the httprepo can use them when pulling via http.
adding a
abort: username 'foo\nbar1' contains a newline
abort: username 'foo\nbar2' contains a newline
transaction abort!
rollback completed
abort: username 'foo\nbar3' contains a newline!