Edited /etc/nova/nova.conf section, "auth_host = controller"

Changed to "auth_host = 10.10.10.51"

Change-Id: I7b2f02169f0edc23a83737f9283c27f5f6508260
Closes-Bug: #1368800
Merge "Edited /etc/nova/nova.conf section, "auth_host = controller""