File editor leftover issue

[jelly]

When someone deletes a file while we are editing we now show a save button, but this will save it as root:root and not as admin:admin because we open the channel as superuser: true.

[leomoty]

I am going to add this here, but it might be nice to do some work to at least dissuade the person from editing binary files:

file -i testleo
testleo: application/octet-stream; charset=binary

Which obviously nothing I do here could have a good outcome, so maybe read-only or something like that?

[jelly]

Yup, we should not offer editing binary files