Core/SAI: Using SMART_TARGET_NONE no longer works the same way as SMART_TARGET_ACTION_INVOKER but rather return NULL instead.

Fixes #10908

src/server/game/AI/SmartScripts/SmartScript.cpp

@@ -2317,7 +2317,6 @@ ObjectList* SmartScript::GetTargets(SmartScriptHolder const& e, Unit* invoker /*
                 if (Unit* u = me->AI()->SelectTarget(SELECT_TARGET_RANDOM, 1))
                     l->push_back(u);
             break;
-        case SMART_TARGET_NONE:
         case SMART_TARGET_ACTION_INVOKER:
             if (scriptTrigger)
                 l->push_back(scriptTrigger);
@@ -2541,6 +2540,7 @@ ObjectList* SmartScript::GetTargets(SmartScriptHolder const& e, Unit* invoker /*
             break;
         }
         case SMART_TARGET_POSITION:
+        case SMART_TARGET_NONE:
         default:
             break;
     }