chgserver: remove _clearenvaliases
Since we expand environment variables in alias lazily, the _clearenvaliases
hack is no longer necessary.
This resolves an issue that a non-shell alias which has environment variables
in its arguments and is set to use pager will not use pager running with chg.
init repo
$ hg init foo
$ cd foo
ill-formed config
$ hg status
$ echo '=brokenconfig' >> $HGRCPATH
$ hg status
hg: parse error at * (glob)
[255]
alias having an environment variable and set to use pager
$ rm $HGRCPATH
$ cat >> $HGRCPATH <<'EOF'
> [ui]
> formatted = yes
> [extensions]
> pager =
> [pager]
> pager = sed -e 's/^/P/'
> attend = printa
> [alias]
> printa = log -T "$A\n" -r 0
> EOF
$ A=1 hg printa
P1
$ A=2 hg printa
P2