fix: emit progress 0 if get_backup() fails

Author: link2xt

src/imex/transfer.rs

@@ -353,6 +353,9 @@ pub async fn get_backup(context: &Context, qr: Qr) -> Result<()> {
                     Err(format_err!("Backup reception cancelled"))
                 })
                 .await;
+            if res.is_err() {
+                context.emit_event(EventType::ImexProgress(0));
+            }
             context.free_ongoing().await;
             res?;
         }