Provide a mean to overwrite group icon for staging dashboard

[coolo]

In the light of #8735, I set gravatar icons for the review groups involved in leap reviews and I can't say it improves the page.

While gravatar icons (while too large) make it nicely obvious that we're looking for a review from @mschnitzer in one case:

16x16 pixels make it really hard to find an avatar that renders okayish (especially on that orange background :)

Having a fontawesome pick to be scaled to the exact size needed would improve overview by a lot. Forcing users to pick a gravatar that looks like a logo on the dashboard does not work :(

[lnussel]

👍

[coolo]

This just became a blocker as I noticed that adding dummy email addresses to groups disables email notificatons to group members. As such I will remove the dummy email addresses again - and then we're back to all review groups looking like me.

[mschnitzer]

reviewed btw ;-)

[coolo]

you broke my test case? :)

[mschnitzer]

@coolo I'll work on it next week ;-)

[coolo]

So many coolos!