test: remove timeout from pop_sent_msg_ex()

Arbitrary timeouts often result in flaky tests,
especially if CI runners may be paused.
In this case however timeout was not used by any tests
and only slowed down the tests in cases where
no message is expected but non-zero timeout is set.

src/mimeparser/mimeparser_tests.rs

@@ -1,6 +1,5 @@
 use mailparse::ParsedMail;
 use std::mem;
-use std::time::Duration;
 
 use super::*;
 use crate::{
@@ -1435,7 +1434,7 @@ async fn test_intended_recipient_fingerprint() -> Result<()> {
     let chat_id = chat::create_group(t, "").await?;
 
     chat::send_text_msg(t, chat_id, "hi!".to_string()).await?;
-    assert!(t.pop_sent_msg_opt(Duration::ZERO).await.is_none());
+    assert!(t.pop_sent_msg_opt().await.is_none());
 
     for (i, member) in members.iter().enumerate() {
         let contact = t.add_or_lookup_contact(member).await;