Fix error with synchronizing time on Ubuntu
Fix error with synchronizing time on Ubuntu

On Ubuntu NTP daemon is called 'ntp' instead of
'ntpd'

Change-Id: I639dd002949437cc98169428721186d27ab8fc94

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