Core/Maps: Removed MapInstanced - no longer neccessary for grid data reference counting (moved to TerrainInfo)

Port From (https://github.com/TrinityCore/TrinityCore/commit/fbe0b8efebca3bc2662b477bdf45627f9783d6c2)

Source/Game/Movement/Generators/FlightPathMovementGenerator.cs

@@ -109,7 +109,7 @@ namespace Game.Movement
                         break;
 
                     if (_currentNode == _preloadTargetNode)
-                        PreloadEndGrid();
+                        PreloadEndGrid(owner);
 
                     _currentNode += (departureEvent ? 1 : 0);
                     departureEvent = !departureEvent;
@@ -262,14 +262,17 @@ namespace Game.Movement
             else
                 _preloadTargetNode = (uint)nodeCount - 3;
 
+            while (_path[(int)_preloadTargetNode].ContinentID != _endMapId)
+                ++_preloadTargetNode;
+
             _endGridX = _path[nodeCount - 1].Loc.X;
             _endGridY = _path[nodeCount - 1].Loc.Y;
         }
 
-        void PreloadEndGrid()
+        void PreloadEndGrid(Player owner)
         {
             // Used to preload the final grid where the flightmaster is
-            Map endMap = Global.MapMgr.FindBaseNonInstanceMap(_endMapId);
+            Map endMap = owner.GetMap();
 
             // Load the grid
             if (endMap != null)