Get clean version tag name

[AndreasAmMueller]

I got to work on a repository with multiple versions for different projects within that repository (mono repository).

The tags are named with folders

• project1/v1.0.0
• project1/v1.2.3
• project2/v0.1.0
• project2/v0.5.1

The directory.build.props have their <NrtTagMatch>project1/v[0-9]*</NrtTagMatch> and <NrtTagMatch>project2/v[0-9]*</NrtTagMatch> set properly.

to get clean versions, the change is required.