直播截图改为只在直播期间获取，直播结束后将一只显示上一次直播间的截图

src/dsb/com/cnd3b/service/GetPolyvAnalysisData.java

@@ -93,8 +93,6 @@ public class GetPolyvAnalysisData extends BaseClass implements Runnable {
                         String siteid = map.get(channelid).get(0).getString("siteid");
                         createLiveMessage(siteid, tagentsid);
                     }
-                } else if (livestatus.equalsIgnoreCase("waiting")) {
-                    sqllist.add("update tlive set livestatus='" + livestatus + "',channelcoverimageurl='" + polyv.getChannelImage(channelid, livestatus) + "' where channelid='" + channelid + "'");
                 } else {
                     sqllist.add("update tlive set livestatus='" + livestatus + "' where channelid='" + channelid + "'");
                 }