Fix encoding issues in MiraiCode.hpp

Author: Numendacil

include/mirai/messages/MiraiCode.hpp

@@ -39,7 +39,7 @@ namespace Cyan
 		virtual bool Set(const json& json) override
 		{
 			if (json["type"].is_null() || json["type"].get<string>() != this->GetType())
-				throw std::runtime_error("¸ø¶¨µÄjson²»ÕýÈ·");
+				throw std::runtime_error("给定的json不正确");
 			code_ = json["code"].get<string>();
 			return true;
 		}