Description of problem:

In PF5 Settings, tab Tasks, field Task troubleshooting URL, the description says:

 Url
 pointing to the task troubleshooting documentation. It should contain 
%{label} placeholder, that will be replaced with normalized task label 
(restricted to only alphanumeric characters)). %{version} placeholder is
 also available.

It allows me to change the value to something that is not URL, like "xx".

How reproducible:

Deterministic, at least on stream 122.0 and 6.17.

Is this issue a regression from an earlier version:

No

Steps to Reproduce:

1. Have a Satellite with new PF5 Settings

2. Got to Administer -> Settings -> tab Tasks

3. Set "Tasks troubleshooting URL" = "xx", confirm

Actual behavior:

Success

Expected behavior:

Error, that value is not URL. Optionally, it can also validate that the value contains %{label} placeholder because the value SHOULD contain it, as per description.