Django how to turn off warning

Question

I have a special user model, with own auth backend. It's good that Django take care about me and send notifications, but how i can turn off some warnings, like this:

WARNINGS:
profile.User: (auth.W004) 'User.email' is named as the 'USERNAME_FIELD', but it is not unique.
    HINT: Ensure that your authentication backend(s) can handle non-unique usernames.

My user model:

class User(AbstractBaseUser, PermissionsMixin):
    email = models.EmailField(_('email address'))
    site = models.ForeignKey(Site, verbose_name=_("Site"), null=True, blank=True)
    class Meta:
        unique_together = (
            ("email", "site", ),
        )

Answer 1

While looking into the settings documentation for a project of my own I stumbled upon a setting that reminded me of your question.

Since Django 1.7 there is a setting to silence certain warnings. If you are using Django 1.7 or later you can add the error code to the SILENCED_SYSTEM_CHECKS setting:

# settings.py

SILENCED_SYSTEM_CHECKS = ["auth.W004"]

Source: https://docs.djangoproject.com/en/1.7/ref/settings/#silenced-system-checks