Line numbers for transcription not appearing in admin transcription editor (but they appear fine on the public site)

[kseniaryzhova]

Describe the bug
When looking at a doc detail page in the admin interface, the transcriptions do not have line numbers in the transcription editor display.

To reproduce
Steps to reproduce the behavior:

1. Go to admin site.
2. Navigate to a doc detail page with a transcription
3. See error.

Expected behavior
I expect the transcription editor display to look the same in admin and on the public site, i.e. if line numbers are present, they should be visible on both admin and public.

Screenshots

But it works fine on public: