Port validation does not allow 5 digit ports

Port validation (in link_validate_url) has the following match for port

$port = '(:([0-9]{1,4}))';

This prevents inserting URLs with 5 digit ports. Since the valid port range is 1 to 65535 - this blocks off quite a few valid ports.

A quick fix is to set 1,4 to 1,5 - but this is non-optimal - since it allows 65536-99999 too. However - I can't see an easy way to fix that issue with just regex pattern matching.