interrupt is used as a suicide signal for executors, so go back to the top if...

interrupt is used as a suicide signal for executors, so go back to the top if that was why we were interrupted. Unlikely race condition, but still...

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@34159 71c3de6d-444a-0410-be80-ed276b4c234a