docs: correct the accepted value for X-XSS-Protection header (#11015)

Signed-off-by: heylongdacoder <heylongdacoder@gmail.com>

docs/configuration/https.md

@@ -90,7 +90,7 @@ http_server_config:
     # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
     [ X-Content-Type-Options: <string> ]
     # Set the X-XSS-Protection header to all responses.
-    # Unset if blank. Accepted value is nosniff.
+    # Unset if blank.
     # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-XSS-Protection
     [ X-XSS-Protection: <string> ]
     # Set the Strict-Transport-Security header to HTTP responses.