Clarify UTD notice about no messages to unverified devices

[tuxayo]

It's a copy of the message from Riot Web which is much clearer.

Pull Request Checklist

• Changes has been tested on an Android device or Android emulator with API 16

Is that needed for a string change?

• UI change has been tested on both light and dark themes

Is that needed for a string change?

• Pull request is based on the develop branch
• Pull request updates CHANGES.md

Is that needed for a string change?

• Pull request includes screenshots or videos if containing UI changes

Is that needed if the string is shorter?

• Pull request includes a sign off

[BillCarsonFr]

Thanks for the PR

Actually it's more than just the copy, we need to implement MSC2399 matrix-org/matrix-spec-proposals#2399
The sender will now give more information, it'll be then possible to say if the message cannot be decypted because you are black-listed, or your device is not verified, or if it's a real issue with key share

It's tracked here -> #797

and coming very soon

[tuxayo]

Actually it's more than just the copy, we need to implement MSC2399 matrix-org/matrix-spec-proposals#2399
The sender will now give more information, it'll be then possible to say if the message cannot be decypted because you are black-listed, or your device is not verified, or if it's a real issue with key share

How does Riot Web work currently? Does it assume «The sender has disabled encrypting to unverified devices»?
And RiotX Android for now doesn't make that assumption.

[BillCarsonFr]

Actually it's more than just the copy, we need to implement MSC2399 matrix-org/matrix-doc#2399
The sender will now give more information, it'll be then possible to say if the message cannot be decypted because you are black-listed, or your device is not verified, or if it's a real issue with key share

How does Riot Web work currently? Does it assume «The sender has disabled encrypting to unverified devices»?
And RiotX Android for now doesn't make that assumption.

according to MSC the client is sending a to_device message m.room_key.withheld to the device that will not receive the keys