Branch name

[isalgueiro]

Hi all, and thanks for your work in this plugin!

We're getting some weird branch name substrings when using this. For some projects this is cutting out the first letter of the branch name:

gradle-git-version/src/main/java/com/palantir/gradle/gitversion/VersionDetailsImpl.java

Line 166 in 4216f47

return ref.getName().substring(Constants.R_HEADS.length());

Why is that substring needed at all? As per jgit docs, we should already have the short branch name in git.getRepository().getBranch(): https://download.eclipse.org/jgit/site/5.8.0.202006091008-r/apidocs/org/eclipse/jgit/lib/Repository.html#getBranch--

Thanks!