Can not log out additional account which does not be authenticated yet

[Jin]

Description:
Telegram can not log out additional account which does not pass the authentication yet.

Reproduce Steps:
  a) Launch Telegram
  b) Log in account: A
  c) Select "Add Account" in settings to login account: B
  d) Select country code and enter phone number
  e) Click back key to cancel the SMS authentication
  f) Select "Settings" in settings
  g) Click "Log out | account: B"
  h) Observe the result in settings

Occurrence:
10/10 (100%)

Actual Result:
Telegram does not log out the account: B well.

Expected Result:
Telegram can log out the account no matter it is authenticated or not.

Click package:
    com.ubuntu.telegram (2.0.4.1)

[Jin (jindallo)]

Before the step e),
we could switch the app. to background firstly,
then switch back to the app. so we can get unauth. account shown on the settings menu.

[Jin (jindallo)]

Since there is also a file: profiles.sqlite which records the account user input,
emit a signal: delete account will be a better solution if the authentication process does not be completed.

Need to check if there is the function/method: deleteAccount().

[Jin (jindallo)]

For this bug, we summarize the pass criteria:
    1. no show unauthenticated account under "Accounts" section in Telegram settings menu
    2. no /home/phablet/.config/com.ubuntu.telegram/<phone_number> folder and related information in profiles.sqlite
    3. no /home/phablet/.cache/com.ubuntu.telegram/<phone_number> folder

[Jin (jindallo)]

This issue is fixed by UX flow changes,
so change the status to "Fix Committed".