doc: align maxHeaderSize default with current value

PR-URL: #41183
Reviewed-By: Robert Nagy <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Ricky Zhou <[email protected]>
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>
Reviewed-By: Mohammed Keyvanzadeh <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: kanongil

doc/api/http.md

@@ -3002,7 +3002,7 @@ added:
 * {number}
 
 Read-only property specifying the maximum allowed size of HTTP headers in bytes.
-Defaults to 8 KB. Configurable using the [`--max-http-header-size`][] CLI
+Defaults to 16 KB. Configurable using the [`--max-http-header-size`][] CLI
 option.
 
 This can be overridden for servers and client requests by passing the