Since Gravatar is an external image source and not perfect from a
privacy perspective, forbidding it allows to improve privacy.
This commit also simplifies and optimizes the avatar code.
Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>
To prevent further weakening of our CSP policies, moving the Avatars
into a non-inline version is the way to go.
This implementation probably needs some beautification. But already fixes
the bug.
Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>
