Core/Unit: Check if NPC is on a transport before sending StopMoving() -packet (normally shipped when trying to speak to moving NPCs) - fixes creatures falling off boats etc.

Thanks to Socolin for hunting down and patching this annoying bug.

--HG--
branch : trunk

src/server/game/Entities/Unit/Unit.cpp

@@ -14481,8 +14481,9 @@ void Unit::StopMoving()
     //if (fabs(GetPositionZ() - z) < 2.0f)
     //    Relocate(GetPositionX(), GetPositionY(), z);
     //Relocate(GetPositionX(), GetPositionY(),GetPositionZ());
-
-    SendMonsterStop();
+    
+    if (!(GetUnitMovementFlags() & MOVEMENTFLAG_ONTRANSPORT))
+        SendMonsterStop();
 }
 
 void Unit::SendMovementFlagUpdate()