mirror/ubuntu: avoid the base packages configuration failure
mirror/ubuntu: avoid the base packages configuration failure

Suppress setting the services startup order in the temporary chroot so
the base packages get configured properly. Makes it possible to install
non-trivial packages in the chroot. As a side effect the scary error
messages "Errors were while processing: <long-list-of-base-packages>"
are elimitated.

blueprint support-ubuntu-trusty
Change-Id: I558dbc7aff4de54d9295345d9ca3d4dc65c9fea8

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