RedWarn will fail to post additional text in the warning template

Per the RW talkpage:

I tried to use Template:uw-notcensored2 with additional text and a Wikipedia diff link in [ http:/ TEXT ] format and posted. The additional text was lost and only the standard template was posted

Expected Behavior

RW posts the template with the added text

Current Behavior

The added text gets lost

Steps to Reproduce

1. Go to https://en.wikipedia.org/wiki/User_talk:Sandbox_for_user_warnings
2. Click Warn User and choose uw-notcensored2 (note: only tested for that template; might occur in more cases)
3. Add a line in the additional info which contains at least one link using the [link test] format
4. Observe

Some information

Operating system: Talk page report, not provided Browser version (e.g. Chrome 80): Talk page report, not provided

Exception, error or logs

Talk page report, not provided