Switch to 5.12.12 release
Switch to 5.12.12 release

Previous build failure looks like it's just a temporary

Signed-off-by: Geoff Hutchison <9cf35bacc9f8512ca007341c9e919cf5dc03e0c7@gmail.com>

OpenChemistry/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs