Removed the Support Email setting

**What does this MR do?**
it removes the support_email param in the gitlab.yml config file

**Why was this MR needed?**
It looks like it is not used anymore so its a little cleaner not to have it around

**Anything reviewer need to watch out for?**
Well, i did a grep for support_email, and did not found any occurrences of it anymore. But please wait to see if CI will fail on anything support_email related.