查询群成员数量
<p><strong>请求示例</strong></p>
<pre><code>{
"data" : {
"room_chat_id" : "R:10696050515072760"
},
"type" : 2554
}
</code></pre>
<p><strong>返回示例</strong></p>
<pre><code>{
"data" : {
"room_chat_id" : "R:10696050515072760",
"room_member_count" : 4
},
"error" : 0,
"type" : 12554
}</code></pre>