chore: make spellcheck happy

apps/emqx_dashboard/i18n/emqx_dashboard_i18n.conf

@@ -37,7 +37,7 @@ Note: `sample_interval` should be a divisor of 60, default is 10s."""
   }
   num_acceptors {
     desc {
-      en: "Socket acceptor pool size for TCP protocols. default is the number of schedulers online"
+      en: "Socket acceptor pool size for TCP protocols. Default is the number of schedulers online"
       zh: "TCP协议的Socket acceptor池大小, 默认设置在线的调度器数量（通常为 CPU 核数）"
     }
     label {