Trying to add Microsoft account when offline

[phit]

Operating System

Windows, macOS

Description of bug

Adding an account when offline gets stuck

Steps to reproduce

• Be offline, e.g. setting an invalid proxy config in MultiMC for easy testing.
• Go to manage accounts and click add Microsoft account
• See the window being stuck at Working.. and cancel being grayed out

Suspected cause

Either enable the cancel button or set a realistic timeout for the task.

This issue is unique

• I have searched the issue tracker and did not find an issue describing my bug.