This is a symptom of #155

Reproduction

1. Set up EWS account
2. Restart Mustang
3. -> EWS mail account is not logged in (verify that)
4. Go to contacts of that account
5. Change a contact, e.g. delete a phone number

Actual result

• Error Cannot read properties of undefined (reading 'callEWS')
• Stack

error.ts:6 TypeError: Cannot read properties of undefined (reading 'callEWS')
    at EWSPerson.save (EWSPerson.ts:136:51)
    at ContactEntryUI.save (PersonDetails.svelte:279:20)
    at index.mjs:1189:20
    at Array.forEach (<anonymous>)
    at index.mjs:1188:31
    at stopEditing (ContactEntryUI.svelte:65:5)
    at HTMLButtonElement.remove (ContactEntryUI.svelte:80:5)
    at index.mjs:1244:44
    at Array.forEach (<anonymous>)
    at HTMLButtonElement.bubble (index.mjs:1244:27)

Expected result

• No error
• Login dialog pops up
• Save happens after login
• If login is not possible, save the change for later, and save it to the server once we login successfully next time (offline capability - might be too much right now)