Fix warning.

Author: AYMENJD

td/telegram/files/ResourceState.cpp

@@ -4,8 +4,6 @@
 // Distributed under the Boost Software License, Version 1.0. (See accompanying
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
-#pragma once
-
 #include "td/telegram/files/ResourceState.h"
 
 #include "td/utils/format.h"