Set Keepalived script_user to root
Set Keepalived script_user to root

Otherwise, Keepalived tries to execute its scripts as
`keepalived_script`, which doesn't exist, so none of the scripts get
executed at all. On top of that, some of the scripts require root
privileges, so `script_user` needs to be set to `root`.

Change-Id: Ia5cc0154cf520132d133679b64fc5f5c698dce85
Closes-Bug: 1806004

openstack/openstack-ansible,openstack/openstack-ansible,stackforge/os-ansible-deployment,stackforge/os-ansible-deployment