Fix file upload with django & filesystem backends

Description

`reverse_lazy` object cannot be dumped by `json.dumps`, which results in
TypeError when attempting to convert the xblock response to json.

Close #1139.

Assignee

David Ormsbee

Reporter

Open Source Pull Request Bot

Contributor Name

Régis Behmo

Repo

edx/edx-ora2

Customer

None

Epic Link

None

OSCM Assignee

None

Platform Map Area (Levels 1 & 2)

Educator Experiences - Content Blocks & interactives

Platform Map Area (Levels 3 & 4)

Core Course Content Blocks - Open Response Assessments

Blended Hour Utilization Percentage

None

Priority

Unset
Configure