openstack: Change MCO port
openstack: Change MCO port

Commit #1180 changed the MCO port from 4900 to 22623, which broke
OpenStack deployments as the replace didn't catch 2 places where the
port was still hardcoded.

In addition, I've decoded the data URL to make the maintenance of this
script easier.

derekhiggins/installer,derekhiggins/installer