Disable NetworkManager when removing it
Disable NetworkManager when removing it

This seems to fix the issue of the undercloud vm dropping its ip
on rhel7, and hasn't caused any connection interruptions in my
testing.

agroup/instack-undercloud,bcrochet/instack-undercloud,bcrochet/instack-undercloud,eprasad/instack-undercloud,dmsimard/instack-undercloud,dpkshetty/instack-undercloud,agroup/instack-undercloud,rdo-management/instack-undercloud,dpkshetty/instack-undercloud,eprasad/instack-undercloud,dmsimard/instack-undercloud,rdo-management/instack-undercloud