Use cluster VIP instead of controller IP in test 'Deploy Heat HA'

In the system test 'Deploy Heat HA' controller IP was used to connect 
to keystone, in this case, in HA mode, need to use cluster VIP 
instead of internal controller IP to successfully connection to keystone.

Closes-Bug: #1369412

Change-Id: I8ce6f9094396a8b203aa9fe8c4b05bd8675199e1
Merge "Use cluster VIP instead of controller IP in test 'Deploy Heat HA'"