Method write_characters

lib/remote/httpmessage.cpp:52–57

	void write_character(char c) override { write_characters(&c, 1); }

	void write_characters(const char* s, std::size_t length) override
	{
		auto buf = m_Message.body().Buffer().prepare(length);
		boost::asio::buffer_copy(buf, boost::asio::const_buffer{s, length});
		m_Message.body().Buffer().commit(length);
	}

	void MayFlush(boost::asio::yield_context& yield) override
	{