empty 1:1 chat when using channel invite link (sometimes)

[adbenitez]

some users get an empty 1:1 chat with me when they use my channel's invite link, I also get empty 1:1 chats for some subscribers when they join

the situation seems related to multi-device since I am using multi-device and the user that complained to me also:

I am using 2.48 in both desktop and android at the time that user sent me that message, on my side I have been noticing the issue but desktop was 2.43 until recently so I don't have enough data to confirm if that was the problem and now it is solved after all devices are 2.48 (EDIT: actually it just happened to me now), I was already 2.48 in all devices when the user complained tho

the user is using 2.46.0 in one device and 2.48.0 in another, so it is unlikely this is a problem of old core before secure-join v3

[link2xt]

At least on the one side this is a documented bug in securejoin that was never fixed:

core/src/chat/chat_tests.rs

Lines 3772 to 3778 in 6235f2a

	// TODO: There is a known bug in `observe_securejoin_on_other_device()`:
	// When Bob joins a group or broadcast with his first device,
	// then a chat with Alice will pop up on his second device.
	// When it's fixed, the 2 following lines can be replaced with
	// `check_direct_chat_is_hidden_and_contact_is_verified(bob1, alice).await;`
	let bob1_alice_contact = bob1.add_or_lookup_contact_no_key(alice).await;
	assert!(bob1_alice_contact.is_verified(bob1).await.unwrap());

Was added in 5034449 as a TODO.