address #925 heuristically

src/imap.rs

@@ -984,6 +984,11 @@ impl Imap {
             }
             // let's manually drop the StopSource
             if interrupt.is_some() {
+                // the imap thread provided us a stop token but might
+                // not have entered idle_wait yet, give it some time
+                // for that to happen. XXX handle this without extra wait
+                // https://github.com/deltachat/deltachat-core-rust/issues/925
+                std::thread::sleep(Duration::from_millis(50));
                 eprintln!("low-level: dropping stop-source to interrupt idle");
                 std::mem::drop(interrupt)
             }