remove drain from executor job

After removing SIGUSR1 handler from executor ( https://github.com/cloudfoundry-incubator/executor/commit/d7c573b8340c5c1061d7741191468372350327cd ) the drain will hang the deployment when the executor jobs has to stop.

@onsi explained nicely in this thread https://github.com/cloudfoundry-incubator/executor/issues/8 that the drain handler will be moved to rep; so, I assume that this is a right path.