fix(gen_rpc): Fix Chinese translation

apps/emqx_conf/i18n/emqx_conf_schema.conf

@@ -976,11 +976,11 @@ until the RPC connection is considered lost."""
   rpc_insecure_fallback {
     desc {
       en: """Enable compatibility with old RPC authentication."""
-      zh: """启用与旧RPC认证的兼容性。"""
+      zh: """兼容旧的无鉴权模式"""
     }
     label {
       en: "RPC insecure fallback"
-      zh: "RPC不安全的后退"
+      zh: "向后兼容旧的无鉴权模式"
     }
   }