httprepo: use content-type application/mercurial-0.1 for POST
Previously, application/octet-stream was used. The content-type is
currently ignored by the server.
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed
error: pretxncommit.nocommits hook failed: no commits allowed
transaction abort!
rollback completed
abort: no commits allowed