Fix regression with version naming

[krzychu124]

Simplest possible fix for unsupported version string supplied to the C# Version constructor

In the future updates we should ensure that last number of version string x.x.x.x will be dedicated for hotfix releases so: 11(12?).<major - stable releases>.<minor - test releases>.<hotfix>

Closes #1566

[originalfoo]

can this be merged, it's making it difficult to test other PRs without alering the whatsnew txt file each time switching between PRs