add support for upload of '.jpeg' files (not just '.jpg')

[basisbit]

apply previously merged PR #9025 into v2.2.x-release

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What does this PR do?

This pull request adds .jpeg to the supported file extensions list, thus allowing users to upload and use such files as presentation in BigBlueButton.

Additional Notes

The presentation file upload feature allows users to select files with various file extensions like .pdf, .ppt, .jpg and others. So far, the /usr/share/meteor/bundle/programs/server/assets/app/config/settings.yml did not include .jpeg and thus files with that file ending were not supported.
.jpg and .jpeg are the same file format. The three letter version is often used because early versions of windows did only allow three letter file endings.

[antobinary]

Thanks for re-targeting 2.2.x!

[basisbit]

@antobinary should I retarget #9084 too?

[antobinary]

#9084 has more disturbance potential. Let's keep it in branch develop so we can have longer time to evaluate the consequences. Thank you for your contributions @basisbit !