Checkmk Werk 13195: Add validation to Documentation URL

ID: 13195 Title: Add validation to Documentation URL Component: Setup Level: 1 Class: Security fix Version: 2.1.0i1 Previous to this Werk the URLs to Documentation were not validated (e.g. in the rule creation dialog). This could have lead to malicious links, e.g. links containing javascript. These links now will be validated. The URL schemes are now restricted to "http" and "https".