2.8 releases show wrong messages when a disappearing message timer is set remotely

[hpk42]

Desktop 2.8 and android 2.8

"You disabled disappearing messages timer" is shown when a remote chat partner (or an own multi-device) actually set a disappearing message timer.

Recreate:

1. create a group with only yourself or with a second member
2. send a "hi" message
3. set a disappearing timer for the chat

Expected: receivers and own multi-device shown "You set disappearing messages timer to ...."
Actual: all receivers show "You disabled disappearing messages timer"

[WofWca]

This change looks sussy

core/src/receive_imf.rs

Lines 1798 to 1806 in 416131b

	// Do not delete the system message itself.
	//
	// This prevents confusion when timer is changed
	// to 1 week, and then changed to 1 hour: after 1
	// hour, only the message about the change to 1
	// week is left.
	ephemeral_timer = EphemeralTimer::Disabled;
	Some(stock_ephemeral_timer_changed(context, ephemeral_timer, from_id).await)

Now better_message is always with EphemeralTimer::Disabled.

Prior to the "key-contacts" MR it first assigned the message, and only after that overrode ephemeral_timer

Introduced in 588b85b of #6796.

[hpk42]

commented ephemeral_timer set out

core/src/receive_imf.rs

Line 1804 in 416131b

ephemeral_timer = EphemeralTimer::Disabled;

and recompiled desktop: it shows epehemeral timer sets correctly then.