revlog: always process opener options I'm not sure when ``opener.options`` would ever be explicitly set to None. It is definitely not possible to construct a repo this way because ``localrepo.resolvestorevfsoptions()`` always returns a dict and ``localrepo.makelocalrepository()`` always sets ``opener.options`` to this value. Because we always execute this code now, if options are empty we defaulted to creating version 0 revlogs. So we had to change the code slightly to fall back to the default revlog version and flags. As astute reader will note that it is not possible to create version 0 revlogs now. However, I don't think it was possible before, as this required ``opener.options`` being unset, which I don't think was possible. I suspect this means our test coverage for version 0 revlog repositories is possibly non-existent! Since I don't see a config option to disable revlog v1, I'm not even sure if we had a way to create new repos with version 0 revlogs! Who knows. Differential Revision: https://phab.mercurial-scm.org/D5559