Under certain conditions, the Locks-and-latches plugin does not prevent jobs
from running simultaneously.

I have 2 jobs (A and B) configured to aquire the same lock.

• "Build now" job A, it starts to run
• "Build now" job B, it remains in the queue
• "Build now" job A again while the previously scheduled build is is still running
  ---> in the queue: A and B
• the first build of A finishes
  --> both builds from the queue start simultaneously!

Expected: one job from the queue wins and is built first.

Maybe related to bug 2083