Update doc/api/url.md

Applied @aduh95's suggestion.

Co-authored-by: Antoine du Hamel <[email protected]>

Author: deokjinkim

doc/api/url.md

@@ -251,7 +251,7 @@ const myURL = new URL('https://example.org:81/foo');
 console.log(myURL.hostname);
 // Prints example.org
 
-// Setting the hostname does not change the port
+// Setting an invalid hostname is ignored:
 myURL.hostname = 'example.com:82';
 console.log(myURL.href);
 // Prints https://example.org:81/foo