Cannot delete S3 files

[swisscat]

When a file is uploaded on a S3 bucket, the function :function prefixes a slash in front of the filename, which prevents proper resource deletion.

Looks like the ItemModel refactor adds an unecessary slash in front of the Delete command, which produces a command equivalent to (double slash)

swisscat@swisscat:~$ aws s3 rm s3://<bucket>//var/file.pdf
fatal error: An error occurred (404) when calling the HeadObject operation: Key "/var/file.pdf" does not exist

Commit swisscat@912f2fa fixes the issue, however, I suspect it might not be generic enough.

[swisscat]

Fixed with 49de88e.