Default avatar goes invisible when friend comes online

[anthonybilinski]

Commit hash: 89198f5

Reproducible: Always

Steps to reproduce

1. Have friend come online with default avatar

Observed Behavior

1. If user is selected, their avatar switches from black to white, which makes it nearly invisible on the white background
2. If user is not selected, their avatar switches from white to black, also nearly invisible on the black background

Problem is a boolean flip in FriendWidget::onAvatarRemoved, PR incoming