[fix] 修复客户端负载问题

wu-lazy-cloud-heartbeat-common/src/main/java/org/framework/lazy/cloud/network/heartbeat/common/ChannelContext.java

@@ -119,6 +119,10 @@ public class ChannelContext {
             return null;
         }
         channels = channels.stream().filter(Channel::isActive).collect(Collectors.toList());
+        if(ObjectUtils.isEmpty(channels)){
+            return null;
+        }
+        // TODO  负载问题
         return channels.get(0);
     }