Remove env1 section from deployment template

[MrCreosote]

Can just use the additional_config section and reduce complexity, rather than having one special case.

E.g. remove these lines:

https://github.com/kbase/auth2/blob/master/deployment/conf/.templates/deployment.cfg.templ#L23-L24
https://github.com/kbase/auth2/blob/master/deployment/conf/.templates/deployment.cfg.templ#L33-L34
https://github.com/kbase/auth2/blob/master/deployment/conf/.templates/deployment.cfg.templ#L43-L44

Need to coordinate with devops before this happens as they'll need to change their config in lockstep.