fix: Remove group member locally even if send_msg() fails (#5508)

Otherwise it's impossible to remove a member with missing key from a protected group. In the worst
case a removed member will be added back due to the group membership consistency algo.

src/webxdc.rs

@@ -2588,6 +2588,7 @@ sth_for_the = "future""#
         );
 
         remove_contact_from_chat(&alice, chat_id, contact_bob).await?;
+        alice.pop_sent_msg().await;
         let status =
             helper_send_receive_status_update(&bob, &alice, &bob_instance, &instance).await?;