[CVAT-UI] Fixed displaying on canvas in some cases

[bsekachev]

Motivation and context

One of bugs affects some functionality, more specific - propagation (reported on gitter).
Resolve #1819

How has this been tested?

Manual testing

Checklist

• I submit my changes into the develop branch
• I have added 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) 2020 Intel Corporation
#
# SPDX-License-Identifier: MIT

[coveralls]

Pull Request Test Coverage Report for Build 6285

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.02%) to 65.141%

---

Files with Coverage Reduction	New Missed Lines	%
cvat/apps/engine/media_extractors.py	5	76.18%

Totals
Change from base Build 6272:	-0.02%
Covered Lines:	11045
Relevant Lines:	16548

---

💛 - Coveralls

[csgwon]

I've confirmed that it now works. Thanks for the fix!!!

[bsekachev]

@csgwon Great, I will close the #1838