[2.5.1.1] Scoping error in adopt_tribalism decision

[richvh]

      FROM = {
         primary_title = {
           ROOT = {
             custom_tooltip = {
               text = TT_KHAN_INDEPENDENCE
             }
             most_prestigious_clan_vassal = {
               custom_tooltip = {
                 text = TT_NEW_KHAN

The other nomad adopt other government decisions use FROM in place of ROOT. I believe the use of ROOT here is a bug, as ROOT is a settlement and settlements don't have vassals.