eg, git-annex enableremote foo encryption=none will not remove encryption,
and other encryption= settings don't change the type of encryption used.
Either of which would render data stored in a special remote inaccessible.
Probably fixes reversion introduced in
71f78fe45d.
That commit got rid of the hasEncryptionConfig check, which I think would
have detected this before. I've not gone back to verify that.
Sponsored-by: mycroft
