Allow webhooks URL to have leading and trailing spaces
What does this MR do?
It makes URLs in webhooks valid even if they contain leading and/or trailing spaces.
Are there points in the code the reviewer needs to double check?
No
Why was this MR needed?
Spaces are hard to notice in input fields, this helps users by accepting leading and trailing spaces in webhooks URLs.
What are the relevant issue numbers?
It fixes #13652 (closed).
Screenshots (if relevant)
None