Revert "include stunnel in stunnel::service (https://leap.se/code/issues/3861)"

This reverts commit b6fbb5f013976f6ad1448ac744ae50b2b1aa0bd0.

This removes some pieces of service.pp that shouldn't be removed
fix include stunnel in stunnel::service (https://leap.se/code/issues/3861) - this is what b6fbb5f013976f6ad1448ac744ae50b2b1aa0bd0 should have been