Some smaller fixes

- PGP key of the user shown in the profile instead of always showing N/A

- Contact e-mails now include the instance's owning org in the subject

- Users can now enable/disable contact e-mail subscriptions
Changes to the shadow attribute controller

- users that weren't publishers couldn't accept / discard proposals

- emails were blocked by an incorrect debug mode for the e-mailer
Merge branch 'hotfix-2.1.11'