lists/migrate3x: solve collision between cronie and vixie-cron

The tos3to4-early uses switch-branch that depends on updater-superviser
that in turn depends on cronie. We do not need updater-supervisor to
migrate updater's configuration and thus we can break this dependency
simply by temporally masking updater-supervisor behind virtual setting.
The updater-supervisor is considered as virtual until tos3to4-early is
not installed (here we use actually package we chain after tos3to4-early
to properly detect that). The last run that updates rest of the system
then updates updater-supervisor as usual.

The last change is just minor tweak. We add priority to tos3to4-early.
It is critically requested and thus priority plays no role in satisfying
requests but it is used to order requests and thus should force
tos3to4-early to be planned as soon as possible.
8 jobs for hotfix/lists-fix-invalid-syntax in 10 minutes and 51 seconds (queued for 5 seconds)
Status Name Job ID Coverage
  Build
passed lists_generate #545868

00:00:15

passed medkit_mox #545865

00:10:51

passed medkit_omnia #545866

00:09:32

passed medkit_turris1x #545867

00:04:49

passed prepare_mox #545862

00:03:46

passed prepare_omnia #545863

00:03:45

passed prepare_turris1x #545864

00:03:45

 
  Verify
passed lists_verify #545869

00:00:17