Use server hostname when creating secure websocket
Use server hostname when creating secure websocket

VNC console tests may fail if SSL is terminated on a front-end load
balancer that relies on SNI.

With this change, when SSL wrapping the socket for a wss connection, the
optional server_hostname parameter is included, in order to allow the
server (or SSL terminating entity) to respond with correct certificate.

The create_websocket function is used by the vnc console tests here:
- tempest/api/compute/admin/test_live_migration.py
- tempest/api/compute/servers/test_novnc.py

Change-Id: I8025742607e591821a5e90b5c193ba6cbbc3a241

openstack/tempest,openstack/tempest