luci-app-ssr-plus: Update translate

luci-app-ssr-plus/po/zh-cn/ssr-plus.po

@@ -264,9 +264,6 @@ msgstr "QUIC 流接收窗口"
 msgid "Lazy Start"
 msgstr "延迟启动"
 
-msgid "Disable Path MTU discovery"
-msgstr "禁用 MTU 探测"
-
 msgid "Enable Tunnel(DNS)"
 msgstr "启用隧道（DNS）转发"