Pin swift when using LKG=1
Pin swift when using LKG=1

The current swift has a change that doesn't work with our other
LKG versions.

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