Make https://github.com/christianwgd/mezzanine/commit/002ff9600d2cb0b015fe53f89c9688c2ccbc6b42 backwards compatible with django versions < 2.1
Make https://github.com/christianwgd/mezzanine/commit/002ff9600d2cb0b015fe53f89c9688c2ccbc6b42 backwards compatible with django versions < 2.1

christianwgd/mezzanine,christianwgd/mezzanine,christianwgd/mezzanine