Deprecated function issue when passing NULL to UrlHelper::isExternal()

Update #2 to include check on image url link render array

Sorry for the many comments, seems Im having an off couple of days.
This patch modifies #3 to remove the check for port key which is already being checked inside the conditional. This is throwing an unnecessary log error as it is in #3.

Looks good. Thanks for the contribution

Automatically closed - issue fixed for 2 weeks with no activity.