Arbitrary url max length of 128 characters is too short

Problem/Motivation

I just realized the error of max 128 characters that triggered the original issue was a red herring. The root problem is actually that the url entered in must be of the format "https://blah.com" and I was using the semantically valid "//blah.com". Apparently this is viewed as an internal url by the module and/or drupal.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes