Updated openstack/openstack
Project: openstack/nova  80389939a3ed14ffaed954b86cf3be0bbcb119c7

minor corrections to devref rpc page

Correct wording to proper English and remove extra space between words while
in there.

DocImpact

Change-Id: If4b3d9d81d7193107e84867e4ab713c413a4976d