libravatar's sends email with FROM: accounts@mg.linux-kernel.at

I think it might be related to the following settings in config.py (although it comes before DEFAULT_FROM_EMAIL = os.environ.get('DEFAULT_FROM_EMAIL', 'ivatar@mg.linux-kernel.at') strangely).

SERVER_EMAIL = 'accounts@mg.linux-kernel.at'
DEFAULT_FROM_EMAIL = SERVER_EMAIL

...Actually looking into models.py SERVER_EMAIL varaiable is used as send_email's parameter.

We probably want to:

SERVER_EMAIL = os.environ.get('SERVER_EMAIL', 'accounts@mg.linux-kernel.at')

Or maybe we can just keep DEFAULT_FROM_EMAIL?