Fix SharedMemory declaration

Should be under VCMI_LIB_NAMESPACE_BEGIN

client/CServerHandler.h

@@ -25,13 +25,12 @@ class CGameState;
 struct ClientPlayer;
 struct CPack;
 struct CPackForLobby;
+struct SharedMemory;
 
 template<typename T> class CApplier;
 
 VCMI_LIB_NAMESPACE_END
 
-struct SharedMemory;
-
 class CClient;
 
 class CBaseForLobbyApply;