refactor: upgrade django=2.2.23. Fileupload issue fixed.
refactor: upgrade django=2.2.23. Fileupload issue fixed.

eduNEXT/edx-platform,eduNEXT/edx-platform,edx/edx-platform,edx/edx-platform,arbrandes/edx-platform,angelapper/edx-platform,angelapper/edx-platform,edx/edx-platform,arbrandes/edx-platform,angelapper/edx-platform,angelapper/edx-platform,edx/edx-platform,eduNEXT/edx-platform,eduNEXT/edx-platform,arbrandes/edx-platform,arbrandes/edx-platform