Check for eth1/carrier instead of eth1/operstate
Check for eth1/carrier instead of eth1/operstate

eth1/operstate seems to be 'unknown' sometimes, even if the interface
is up and working as expected.

hustcat/pipework,mirzawaqasahmed/pipework,ksmaheshkumar/pipework,indykish/pipework,OnePaaS/pipework,Rakurai/pipework,PeerXu/pipework,midonet/pipework,mej/pipework,helloIAmPau/pipework,deitch/pipework,hayderimran7/pipework,Altiscale/pipework,bing6/pipework,hansode/pipework,pierrecdn/pipework,spheresh/pipework,mrvicadai/pipework,sharry007/pipework,SivagnanamCiena/pipework,awanke/pipework,wrenth04/pipework,palfrey/pipework,osrg/pipework,haggaie/pipework,ONode/pipework,snowygoose/pipework,zhouqingyu/pipework,abn/pipework,jpetazzo/pipework,JamesGuthrie/pipework,YujiOshima/pipework