Incoming share is falsely returned as outgoing share

## Steps to reproduce
1. As `admin`, share a file with `einstein` using the permissions `17` (read + share)
2. As `einstein`, accept the share
3. As `einstein`, query for outgoing shares: `https://host.docker.internal:9201/ocs/v1.php/apps/files_sharing/api/v1/shares?path=%2F&space_ref=...&reshares=true` -> Empty list, everything is fine
4. As `admin`, change the permissions of this share to `1` (read)
5. As `einstein`, query for outgoing shares again: `https://host.docker.internal:9201/ocs/v1.php/apps/files_sharing/api/v1/shares?path=%2F&space_ref=...&reshares=true` -> The incoming share is being returned here.