Add additional mlab4 nodes to uw_geoloc4 for IPv6.
Add additional mlab4 nodes to uw_geoloc4 for IPv6.

salarcon215/operator,m-lab/operator,nkinkade/operator,critzo/operator,critzo/operator,m-lab/operator,jheretic/operator,jheretic/operator,stephen-soltesz/operator,nkinkade/operator,salarcon215/operator,stephen-soltesz/operator