BUG: 418526
The profile group with the value `Default=1` is not always the default profile, for example:
{F8192502}
In the screenshot you can see that the profile with `Path=vwc2yphi.default` has the value `Default=1`,
but in the about:profiles page in Firefox it is not marked as the default profile.
The correct default profile is in the `[Install4F96D1932A9F858E]` group with the key `Default`.
This patch originated from D28196.