Reduce nodepool's wait between calls in hpcloud

Since we've been put in a higher rate limit tier by hpcloud, try
reducing the wait time between calls to see if it helps get nodes
there out of building and delete states more efficiently.

Change-Id: I6125a461371d2fa7f6d81f9bdeba01896552633f
Merge "Reduce nodepool's wait between calls in hpcloud"