fix wrong identifier used when stopping worker
fix wrong identifier used when stopping worker

PrFalken/exaproxy,david-farrar/exaproxy,PrFalken/exaproxy,david-farrar/exaproxy,jbfavre/exaproxy,david-farrar/exaproxy,PrFalken/exaproxy,jbfavre/exaproxy