revlog: fix resolution of revlog version 0
This partially backs out
cecf3f8bccd3, "revlog: always process opener options."
My understanding is that if there's no "revlog1" nor "revlog2" in .hg/requires,
the repository should stick to the v0 format. The reasoning is briefly
described in
31a5973fcf96, "revlog: get rid of defversion."
Maybe we can drop support for missing opener options, but I didn't do that
in this patch.
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----