Fixed softlock for mod policies overriding existing policy locations

core/src/com/unciv/models/ruleset/Ruleset.kt

@@ -345,6 +345,16 @@ class Ruleset {
                         policy.requires = arrayListOf(branch.name)
                     }
                     policies[policy.name] = policy
+
+                    // If mods override a previous policy's location, we don't want that policy to stick around,
+                    // because it leads to softlocks on the policy picker screen
+                    val conflictingLocationPolicy = policies.values.firstOrNull {
+                        it.branch.name == policy.branch.name
+                            && it.column == policy.column
+                            && it.row == policy.row
+                    }
+                    if (conflictingLocationPolicy!=null)
+                        policies.remove(conflictingLocationPolicy.name)
                 }
 
                 // Add a finisher