[Core] Remove obsolete directive

src/framework/GameSystem/GridReference.h

@@ -34,7 +34,7 @@ template<class OBJECT>
  * @brief
  *
  */
-class MANGOS_DLL_SPEC GridReference : public Reference<GridRefManager<OBJECT>, OBJECT>
+class  GridReference : public Reference<GridRefManager<OBJECT>, OBJECT>
 {
     protected:
 

src/framework/Policies/ObjectLifeTime.cpp

@@ -32,7 +32,7 @@ namespace MaNGOS
         std::atexit((void (*)())p);
     }
 
-    void MANGOS_DLL_SPEC at_exit(void (*func)())
+    void  at_exit(void (*func)())
     {
         external_wrapper((void*)func);
     }

src/framework/Policies/ObjectLifeTime.h

@@ -41,7 +41,7 @@ namespace MaNGOS
      *
      * @param (func)()
      */
-    void MANGOS_DLL_SPEC at_exit(void (*func)());
+    void  at_exit(void (*func)());
 
     template<class T>
     /**