NoScript is blocking some videos outright starting with 10.1.9.2rc2 on security level "safer"

STR:

1. Take a clean Tor Browser
2. Set the security slider level to "safer" (click on the onion in the toolbar -> Security Settings... -> drag the slider to the medium level)
3. Load https://developer.mozilla.org/samples/video/chroma-key/index.xhtml
4. You get the message "No video with supported format and MIME type found." without the option to override this in order to watch the video.

Expected results:

The NoScript placeholder allowing to watch the video after clicking on it and confirming.

The last good version is NoScript 10.1.9.2rc1 and the first bad one 10.1.9.2rc2

This got reported on our blog: https://blog.torproject.org/comment/278685#comment-278685