IMAP: Error "Unexpected close" when there is no password and login fails

[benbucksch]

Reproduction

1. Set up IMAP account
2. Delete password (for some reason, we keep losing the password sometimes! That's a different bug)
3. Restart app
4. Select the inbox of the account
5. Click "Login" button

Actual result

• Error banner at the top "Unexpected close"
• Same error in error console. No other errors there.
• Stack

console.js:36 ConnectError: Unexpected close
    at IMAPAccount.connection (IMAPAccount.ts:130:35)
    at async IMAPAccount.hasCapability (IMAPAccount.ts:224:16)
    at async IMAPFolder.listMessages (IMAPFolder.ts:108:11)
    at async loadFolder (MailApp.svelte:40:28)

Expected result

• Error banner "[Account name] Please check your password in settings. [IMAP server error message during login]"
• The error banner has a [Settings] button, which leads to the server settings tab of that specific account.