Adjusting to changed mesos_leader_ui_url field
Adjusting to changed mesos_leader_ui_url field

Fixes mesosphere/marathon#1962
mesosphere/marathon-ui,Raffo/marathon-ui,mesosphere/marathon-ui,watonyweng/marathon-ui,cribalik/marathon-ui,janisz/marathon-ui,yp-engineering/marathon-ui,watonyweng/marathon-ui,cribalik/marathon-ui,Raffo/marathon-ui,yp-engineering/marathon-ui,janisz/marathon-ui