mirror/ubuntu: fix sources.list with USE_MIRROR!=none
mirror/ubuntu: fix sources.list with USE_MIRROR!=none

Pass the USE_MIRROR and MIRROR_UBUNTU_SECURITY variables to submake
so it generates a valid sources.list

Change-Id: I796fa4c8fe0452d975fb57bedbcf332129da0154

AnselZhangGit/fuel-main,AnselZhangGit/fuel-main,dancn/fuel-main-dev,eayunstack/fuel-main,dancn/fuel-main-dev,SergK/fuel-main,dancn/fuel-main-dev,ddepaoli3/fuel-main-dev,teselkin/fuel-main,zhaochao/fuel-main,eayunstack/fuel-main,SergK/fuel-main,stackforge/fuel-main,Fiware/ops.Fuel-main-dev,SmartInfrastructures/fuel-main-dev,ddepaoli3/fuel-main-dev,SmartInfrastructures/fuel-main-dev,Fiware/ops.Fuel-main-dev,huntxu/fuel-main,zhaochao/fuel-main,Fiware/ops.Fuel-main-dev,ddepaoli3/fuel-main-dev,teselkin/fuel-main,AnselZhangGit/fuel-main,Fiware/ops.Fuel-main-dev,stackforge/fuel-main,huntxu/fuel-main,zhaochao/fuel-main,zhaochao/fuel-main,ddepaoli3/fuel-main-dev,teselkin/fuel-main,eayunstack/fuel-main,teselkin/fuel-main,zhaochao/fuel-main,AnselZhangGit/fuel-main,dancn/fuel-main-dev,SmartInfrastructures/fuel-main-dev,SergK/fuel-main,huntxu/fuel-main,stackforge/fuel-main,SmartInfrastructures/fuel-main-dev