Update RebuildLastCompletedBuildAction.java

The Rebuild Last button should point to /{JOB_NAME}/lastCompletedBuild/rebuild rather than /{JOB_NAME}/{JOB_ID}/rebuild
Update RebuildValidatorTest.java

Change Assert check
Merge pull request #27 from andresoderlind/ISSUE-J-22836

[JENKINS-22836] Rebuild Last link out of date