[2.8.0] AI vassals use "de jure duchy claim" CB for a single county

[jruderman]

The new dejure_duchy_claim CB costs prestige to use. There's code that tries to keep AI rulers from using it unnecessarily:

       OR = { # This ensures that the AI doesn't declare this type of war against someone who only holds one county within the targeted title...
           ROOT = {
               ai = no
           }
           any_de_jure_vassal_title = {
               count = 2
               tier = count
               holder_scope = {
                   same_realm = FROM
               }
           }
       }

But the "same_realm" check is too lenient for a vassal considering an attack on a fellow vassal.

That bit should instead be something like:

                   holder_scope = {
                       OR = {
                           character = FROM
                           is_liege_or_above = FROM
                       }
                   }

Attached a save where this just happened. The Despot of Trebizond declared war on the Exarch of Armenia for "Duchy of Trebizond", but Armenia only controls one county there.