wireprotov2peer: properly format errors
formatrichmessage() expects an iterable containing dicts with
well-defined keys. We were passing in something else. This caused
an exception.
Change the code to call formatrichmessage() with the proper argument.
And add a TODO to potentially emit the proper data structure from
the server in the first place.
Differential Revision: https://phab.mercurial-scm.org/D4441
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init
$ echo 'base' > base
$ hg ci -Ambase
adding base
$ hg qnew -mmqbase mqbase
$ hg qsave
$ hg qrestore 2
restoring status: hg patches saved state