Set keystone_ec2_url in nova.conf

This is required when keystone is not on the same host as the nova
controller, or when using HA.
(cherry picked from commit 604cce5417b58da1514c3d70ca998563b7d2fa04)
Merge pull request #387 from bkutil/ha_backports

Set keystone_ec2_url in nova.conf
Generate certs on all nodes for HA

With HA, HTTPS and automatic generation of self-signed certificates, all
controller nodes except for one are missing the cert files, and the api
and novncproxy services fail to start.

This is a workaround to generate the certs on all nodes when HA is
enabled.
(cherry picked from commit 7cc8e23b67695ea3ce05088bebec30095e6178db)