Microdown URL references to web locations requiring authentication fail and do not open a browser

[astares]

When within any Microdown handled text (for instance in a class comment) one creates an anchor link to a web
resource that is behind an authentication layer the system gives an error instead of opening the browser as for
other accessible URLs.

For instance if you point in a class comment to a private repo in github https://github.com/myuser/myprivaterepo
the link will not open but Pharo will present the debugger with a MicResourceReferenceError.

To reproduce in Pharo 12:

• create a package "Foo"
• create a class "Bar"
• in the class comment add the following comment

This is a class from [https://github.com/myuser/myprivaterepo](https://github.com/myuser/myprivaterepo)

• save and accept the class comment
• now click on the link in the class comment

=> you get the exception

The expectation is that Pharo also for such URLs just opens the external webbrowser