业务使用memcached时，要指定超时时间等配置

@@ -66,7 +66,10 @@ app.use(session({
     },
     },
     store: new MemcachedStore({
     store: new MemcachedStore({
         hosts: config.memcache.session,
         hosts: config.memcache.session,
-        prefix: 'yohobuy_session:'
+        prefix: 'yohobuy_session:',
+        timeout: 100,
+        retries: 0,
+        reconnect: 5000
     })
     })
 }));
 }));