Do not apply the receiver's color as background color (#864)
Do not apply the receiver's color as background color (#864)

We may want to revert this once the apps do not send avatar images for
every contact (even those who do not have an profile image) any more.
threema-ch/threema-web,threema-ch/threema-web,threema-ch/threema-web,threema-ch/threema-web,threema-ch/threema-web