Added [keystone_authtoken] section in /etc/nova/nova.conf

Closes-bug: #1250606

Change-Id: Id8e0f3521f7628cdd00e1d73d2d6a0db3ca3447b
backport: havana
(cherry picked from commit 672f13d2c5544ec9ea1330f03c39bba0cb33d6ab)
Merge "Added [keystone_authtoken] section in /etc/nova/nova.conf" into stable/havana