Always translate EphemeralTimerChanged message

An EphemeralTimerChanged message with the same timer as already set can
be received when there are large delays or lost messages.  Even though
inner_set_ephemeral_timer should not be called in this case, because it
emits an event indicating timer change, system message will be added to
the chat, so it should be translated with set_better_msg in any case.

src/dc_receive_imf.rs

@@ -663,11 +663,24 @@ async fn add_parts(
         && !is_mdn
         && (*chat_id).get_ephemeral_timer(context).await? != ephemeral_timer
     {
-        match (*chat_id)
+        if let Err(err) = (*chat_id)
             .inner_set_ephemeral_timer(context, ephemeral_timer)
             .await
         {
-            Ok(()) => {
+            warn!(
+                context,
+                "failed to modify timer for chat {}: {}", chat_id, err
+            );
+        } else if mime_parser.is_system_message != SystemMessage::EphemeralTimerChanged {
+            chat::add_info_msg(
+                context,
+                *chat_id,
+                stock_ephemeral_timer_changed(context, ephemeral_timer, from_id).await,
+            )
+            .await;
+        }
+    }
+
     if mime_parser.is_system_message == SystemMessage::EphemeralTimerChanged {
         set_better_msg(
             mime_parser,
@@ -681,22 +694,6 @@ async fn add_parts(
         // hour, only the message about the change to 1
         // week is left.
         ephemeral_timer = EphemeralTimer::Disabled;
-                } else {
-                    chat::add_info_msg(
-                        context,
-                        *chat_id,
-                        stock_ephemeral_timer_changed(context, ephemeral_timer, from_id).await,
-                    )
-                    .await;
-                }
-            }
-            Err(err) => {
-                warn!(
-                    context,
-                    "failed to modify timer for chat {}: {}", chat_id, err
-                );
-            }
-        }
     }
 
     // correct message_timestamp, it should not be used before,