chore: add translations

apps/emqx_dashboard/i18n/emqx_dashboard_i18n.conf

@@ -94,12 +94,12 @@ Note: `sample_interval` should be a divisor of 60."""
   }
   proxy_header {
     desc {
-        en: "Enable support for HAProxy header. Be aware once enabled regular HTTP requests can't be handled anymore."
-        zh: "[FIXME]"
+        en: "Enable support for `HAProxy` header. Be aware once enabled regular HTTP requests can't be handled anymore."
+        zh: "开启对  `HAProxy` 的支持，注意：一旦开启了这个功能，就无法再处理普通的 HTTP 请求了。"
     }
     label: {
         en: "Enable support for HAProxy header"
-        zh: "[FIXME]"
+        zh: "开启对 `HAProxy` 的支持"
     }
   }
   desc_dashboard {

changes/v5.0.15/feat-9802.zh.md

@@ -1 +1 @@
-[FIXME] Support HAProxy protocol for dashboard API.
+现在 dashboard 增加了对 `HAProxy` 协议的支持。