slapos node boot: Start computer partitiong without connecting to master

See merge request !431
3 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed SlapOS-Master.UnitTest-Master

01:37:08

passed SlapOS.Eggs.UnitTest-Master.Python2

00:13:11

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:42