fix neutron l3 with wrong admin_user param
fix neutron l3 with wrong admin_user param

in cluster/manifests/neutron/l3.pp
we define cluster::neutron::l3 with param $admin_username = 'neutron'
but at line 48
fuel call $admin_user instead of $admin_username

The purpose is to set $admin_user to $admin_username

Change-Id: I05533735cfb747a4ca8c75783b410131f4689c2e
Closes-Bug: 1405730

ddepaoli3/fuel-library-dev,eayunstack/fuel-library,xarses/fuel-library,ddepaoli3/fuel-library-dev,huntxu/fuel-library,ddepaoli3/fuel-library-dev,stackforge/fuel-library,huntxu/fuel-library,xarses/fuel-library,stackforge/fuel-library,eayunstack/fuel-library,huntxu/fuel-library,ddepaoli3/fuel-library-dev,xarses/fuel-library,xarses/fuel-library,ddepaoli3/fuel-library-dev,eayunstack/fuel-library,huntxu/fuel-library,eayunstack/fuel-library,huntxu/fuel-library,stackforge/fuel-library,eayunstack/fuel-library,stackforge/fuel-library