Team Avatar is not updated if the team name is numeric.

Bug can be reproduced by following the steps below:

1.   Go to https://bitbucket.org/{team}
   

2.   Click on the top left “Edit avatar”
   

3.   Click on “Select an image” (browse for the image)
   

4.   Click on “Save”
   

This only happens if the name of the team is numeric.