When changing theme, user avatar is changed to default one

[Mateusz Krawczyński]

1. Start Ember
2. Go to settings -> personalization
3. Change theme After the last step, the custom user avatar is replaced with default one.

After restarting the app, the correct avatar is displayed.

[Fredrik Zetterlund]

Fixes Issue #165: When changing theme, user avatar is changed to default one

→ <<cset 35e6a88d5143>>