cmdutil: make amend() take str-keyed opts
I couldn't think of a reasonable change to the signature here, so
unfortunately it keeps the existing one.
Differential Revision: https://phab.mercurial-scm.org/D10862
$ . $TESTDIR/wireprotohelpers.sh
$ hg init server
$ enablehttpv2 server
$ cd server
$ cat >> .hg/hgrc << EOF
> [web]
> push_ssl = false
> allow-push = *
> EOF
$ hg debugdrawdag << EOF
> C D
> |/
> B
> |
> A
> EOF
$ root_node=$(hg log -r A -T '{node}')
$ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log
$ cat hg.pid > $DAEMON_PIDS
lookup for known node works
$ sendhttpv2peer << EOF
> command lookup
> key $root_node
> EOF
creating http peer for wire protocol version 2
sending lookup command
response: b'Bk\xad\xa5\xc6u\x98\xcae\x03mW\xd9\xe4\xb6K\x0c\x1c\xe7\xa0'
$ cat error.log