Version in pet-File not always MAJOR.MINOR.PATCH

We have projects where the version is not MAJOR.MINOR.PATH but rather only MAJOR.MINOR

See e.g. Z:\experiments\2020.06.16_Juelich_IEK6H3_Engstelle\export\simplylife with version 0.8

So, in contrast to what I said in the review for !206 (merged), we do not always have 3 version parts. Currently this means that we don't pass the check and we crash...