Remove extra & conflicting slice tag from gt_bismark
Remove extra & conflicting slice tag from gt_bismark

This is undocumented behavior. Unfortunately not all slice tags behave the same way.

For the 'capabilities' slice tag, a slice only gets one per node. By having:
    "web100_enable_attr + [Attr('MeasurementLabCentos', capabilities='CAP_NET_BIND_SERVICE,vxc_^28'), ]"

There are two, and when calling config multiple times may reset the tag from just "vxc_^28" to 'CAP_NET_BIND_SERVICE,vxc_^28' or back.

    UPDATING : gt_bismark -> (capabilities,None,MeasurementLabCentos)
             : from 'CAP_NET_BIND_SERVICE,vxc_^28' to 'vxc_^28'
    UPDATING : gt_bismark -> (capabilities,None,MeasurementLabCentos)
             : from 'vxc_^28' to 'CAP_NET_BIND_SERVICE,vxc_^28'

This change eliminates the ambiguity.
critzo/operator,jheretic/operator,nkinkade/operator,stephen-soltesz/operator,stephen-soltesz/operator,nkinkade/operator,critzo/operator,m-lab/operator,salarcon215/operator,m-lab/operator,salarcon215/operator,jheretic/operator