Transform IPAddress to string when creating port
Transform IPAddress to string when creating port

If ip address is provided when running nova boot, nova compute
will invoke neutron client to create a port. However, the ip
address parameter is an IPAddress object so neutron client will
fail to send the request to neutron server. Transform IPAddress
object to string to address this issue.

Change-Id: I858cca475748795aa2532f32bfe0f1443b30966f
Closes-Bug: #1408529
(cherry picked from commit 7dfdcbd8835d65cd4a4403c7d575310cf5585474)

eayunstack/nova,eayunstack/nova