Renew website certificate

[abstraktor]

It seems the https://solidity-ide.itemis.com/ certificate has expired.

Is this the right place to report this?

Afterwards, we can re-add the website to https://www.itemis.com/en/it-services/methods-and-tools/xtext. (source: https://github.com/abstraktor/methods-and-tools/blob/master/xtext.md). I commented it out because our linter only allows valid links ;)