RocketMQ agent plugin append trace info lost properties separator

[mxsl-gr]

report bug.
RocketMQ agent plugin tracing lost property separator, when the message has properties.

• when message has properties

TAGS�xxxterminus-request-spanid�xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

• desired properties

TAGS�xxx�terminus-request-spanid�xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

code: cloud.erda.agent.plugin.rocketmq.v4.MessageSendInterceptor:87

SendMessageRequestHeader requestHeader = (SendMessageRequestHeader) context.getArguments()[3];
StringBuilder properties = new StringBuilder(requestHeader.getProperties());
for (Map.Entry<String, String> entry : map.entrySet()) {
    if (entry.getValue() == null) {
        continue;
    }

    properties.append(entry.getKey())
            .append(MessageDecoder.NAME_VALUE_SEPARATOR)
            .append(entry.getValue())
            .append(MessageDecoder.PROPERTY_SEPARATOR);
}