imapc: Fix expunges+appends in same session with imapc_features=no-msn-updates Since the EXPUNGEs were ignored, the sequence numbers weren't updated. When a new mail arrived, the sequence number sent by the remote IMAP server pointed to existing mails in imapc's mapping. Fix this by changing the sequence number if the returned UID is >= next_uid. Fixes "FETCH UID mismatch" errors.