If the avatar file in storage does not exist, it is not an error and
the database can be updated.
See 1be797faba Fix bug on avatar
(cherry picked from commit d2c4d833f4)
The avatar must not be unset in the database if there is a failure to
remove the avatar file from storage (file or S3). The two operations
are wrapped in a transaction for that purpose and this test verifies
it is effective.
See 1be797faba Fix bug on avatar
(cherry picked from commit c139efb1e9)