Fixed bug: tus failed to upload chunk at offset 0 over https

[klakhov]

Motivation and context

Currently if we use tus upload for cvat tasks over https error like this is displayed:

That happens because of incorrect protocol in chunk upload location returned by server. Client makes https request that is forwarded by traefik to django via http. Thats why django's request.build_absolute_uri returns location with http protocol.

There are several ways to let django know that client request was made over https:

• Add custom django configuration setting to use over https
• Add additional header to incoming request using traefik middlewares based on environment
• Modify Location header based on environment using traefik plugin
• Use django's proxy_ssl_header setting as currently traefik provides X-Forwarded-Proto header to determine original client protocol

I've used the last option. Based on SECURE_PROXY_SSL_HEADER setting, if X-Forwarded-Proto is correct, then django knows that request was sent via https.

How has this been tested?

Deployed locally and set secure header to http, X-Forwarded-Proto was http, then django knew that connection was secure and returned https protocol location.

Checklist

• I submit my changes into the develop branch
• I have added a description of my changes into CHANGELOG file
• I have updated the documentation accordingly
• I have added tests to cover my changes
• I have linked related issues (read github docs)
• I have increased versions of npm packages if it is necessary (cvat-canvas,
  cvat-core, cvat-data and cvat-ui)

License

• I submit my code changes under the same MIT License that covers the project.
  Feel free to contact the maintainers if that's a concern.
• I have updated the license header for each file (see an example below)

# Copyright (C) 2021 Intel Corporation
#
# SPDX-License-Identifier: MIT

[klakhov]

@azhavoro Could you look on these settings please? Is it correct that we don't need to change any traefik settings to keep X-Forwarded-* headers visible over https as we do with http?