BE+FE: Unstable devices list (3 status changes in 1h)

Signed-off-by: jokob-sk <jokob.sk@gmail.com>

front/php/templates/language/zh_cn.json

@@ -218,6 +218,7 @@
     "Device_Shortcut_Favorites": "收藏",
     "Device_Shortcut_NewDevices": "新设备",
     "Device_Shortcut_OnlineChart": "设备统计",
+    "Device_Shortcut_Unstable": "",
     "Device_TableHead_AlertDown": "提醒宕机",
     "Device_TableHead_Connected_Devices": "链接",
     "Device_TableHead_CustomProps": "属性",
@@ -789,4 +790,4 @@
     "settings_system_label": "系统",
     "settings_update_item_warning": "更新下面的值。请注意遵循先前的格式。<b>未执行验证。</b>",
     "test_event_tooltip": "在测试设置之前，请先保存更改。"
-}
+}