We are in string freeze for the master branch now. This means that only tiny bugfixes can be accepted, which don’t change any strings, to make sure they don’t break translations.
That should lead us to another stable point release, 0.9.3, hopefully in a week or two.
Here are the mounts that are associated with Sigma 17-70mm f/2.8-4.5 DC Macro in the LensFun config: Sigma, Canon EF, Nikon F AF, Pentax KAF.
If your mount is NOT a Nikon F AF, and you still can use that lens, then it's probably a mistake in the LensFun config.