This option is only relevant if you choose Verisium Manager Version < 19.09.
If the Verisium Manager version is smaller than 19.09, the report is being retrieved by parsing the html web page of the report generated using http connection.
Since Verisium Manager Web Server is having by default a self-signed certificate, normal http connection will fail to get validated and the connection will get rejected.
If you replaced the server certificate with a signed one of your own, you can leave it as default. Unless, if you are using the default Verisium Manager installed self-signed certificate - the only way to overcome its SSL validation is to allow the connection from the Jenkins to the Verisium Manager server at the time of the report retrieval only to skip validation.