缓存push_id有效期

application/chat/service/ChatService.php

@@ -736,7 +736,7 @@ class ChatService
         $redis = RedisExt::getRedis();
         $push_old = $redis->get($key);
         if ($push_old != $push_id) {
-            $redis->set($key, $push_id);
+            $redis->set($key, $push_id, 2592000); //30天有效期
         }
         return true;
     }