Core/Misc: Improve assert message with more detail

src/server/game/Maps/Map.h

@@ -711,7 +711,7 @@ class TC_GAME_API Map : public GridRefManager<NGridType>
 
         NGridType* getNGrid(uint32 x, uint32 y) const
         {
-            ASSERT(x < MAX_NUMBER_OF_GRIDS && y < MAX_NUMBER_OF_GRIDS);
+            ASSERT(x < MAX_NUMBER_OF_GRIDS && y < MAX_NUMBER_OF_GRIDS, "x = %u, y = %u", x, y);
             return i_grids[x][y];
         }