Project avatar with same filename as previous will not be replaced

After updating project avatar, old avatar is used.

To reproduce the problem:

1. set avatar to project from file, e.g. i.png
2. change i.png on your computer
3. remove avatar from project and set changed i.png avatar
4. you will see as avatar, old, untouched i.png

Simple fix is (on client-side):

rename i.png to i2.png and try upload avatar again.