Revert "fix: check UIDNEXT with a STATUS command before going IDLE"

This reverts commit 2e50abe.

STATUS is broken on mail.163.com.
It returns `STATUS "INBOX" ()` reply
when `STATUS "INBOX" (UIDNEXT)` is requested.

src/imap/idle.rs

@@ -9,7 +9,7 @@ use super::session::Session;
 use super::Imap;
 use crate::config::Config;
 use crate::context::Context;
-use crate::imap::{client::IMAP_TIMEOUT, get_uid_next, FolderMeaning};
+use crate::imap::{client::IMAP_TIMEOUT, FolderMeaning};
 use crate::log::LogExt;
 
 const IDLE_TIMEOUT: Duration = Duration::from_secs(23 * 60);
@@ -29,29 +29,6 @@ impl Session {
             return Ok(self);
         }
 
-        // Despite checking for unsolicited EXISTS above,
-        // we may have missed EXISTS if the message was
-        // received when the folder was not selected.
-        let status = self
-            .status(folder, "(UIDNEXT)")
-            .await
-            .with_context(|| format!("STATUS (UIDNEXT) error for {folder:?}"))?;
-        if let Some(uid_next) = status.uid_next {
-            let expected_uid_next = get_uid_next(context, folder)
-                .await
-                .with_context(|| format!("failed to get old UID NEXT for folder {folder}"))?;
-            if uid_next > expected_uid_next {
-                info!(
-                    context,
-                    "Skipping IDLE on {folder:?} because UIDNEXT {uid_next}>{expected_uid_next} indicates there are new messages."
-                );
-                return Ok(self);
-            }
-        } else {
-            warn!(context, "STATUS {folder} (UIDNEXT) did not return UIDNEXT");
-            // Go to IDLE anyway if STATUS is broken.
-        }
-
         if let Ok(()) = idle_interrupt_receiver.try_recv() {
             info!(context, "skip idle, got interrupt");
             return Ok(self);