In the git plugin, when multiple repository URLs are configured (note: two remotes, not MultiSCM), building a git tag does not find the correct commit.

Steps to reproduce:

1. Create a job with two git repository URLs (note: two remotes, not MultiSCM). Ensure you name give the second one a different remote name. For example:

   origin -> git://github.com/blt04/jenkins-test1.git
   upstream -> git://github.com/blt04/jenkins-test2.git
   

2. Run a build using master
3. Configure the branch to be a tag: "test2-1.0"
4. Run the job

Expected results:
Builds the tag

Actual results:
Builds the last built revision