on_play/on_publish hook 新增protocol字段 (#4133 #4143)

对于webhook  涉及到media info的相关信息，增加protocol 的字段，表明是基于什么协议传输的

src/Rtp/RtpProcess.cpp

@@ -127,6 +127,7 @@ bool RtpProcess::inputRtp(bool is_udp, const Socket::Ptr &sock, const char *data
         fwrite((uint8_t *) data, len, 1, _save_file_rtp.get());
     }
     if (!_process) {
+        _media_info.protocol = is_udp ? "udp" : "tcp";
         _process = std::make_shared<GB28181Process>(_media_info, this);
     }