Can't remove or edit single email account on Geary

Once you have added a single account, the 'Accounts' dialogue will not allow you to remove or edit that account (the 'remove account' button is greyed out and non-functional). The only way to remove the account is to add another, then you are permitted to remove the first.

This was in particular a problem for me, because I added an account in error (mistakenly added the non-SSL settings, which are insecure), and then could not alter that, without digging up a secondary, unused account.