LibWeb: Fix double percent encode of username

URL::set_username will apply a percent encode, so we don't need to do
it a second time here.

Userland/Libraries/LibWeb/HTML/HTMLHyperlinkElementUtils.cpp

@@ -114,7 +114,7 @@ void HTMLHyperlinkElementUtils::set_username(DeprecatedString username)
         return;
 
     // 4. Set the username given this’s URL and the given value.
-    url->set_username(AK::URL::percent_encode(username, AK::URL::PercentEncodeSet::Userinfo));
+    url->set_username(username);
 
     // 5. Update href.
     update_href();