Fix S3 Direct Upload on 9.10

S3 Direct Upload does not currently work on 9.10. Blobs are not copied to the main s3 storage bucket upon document creation.

To reproduce:

• prepare a Nuxeo instance with all hot fixes (to HF29),  amazon-s3-online-storage (1.8.7) and amazon-s3-direct-upload (1.0.0) Marketplace packages
• include nuxeo.s3storage configuration in nuxeo.conf (see showconf.txt for exact parameters)
• start Nuxeo and upload a file.
• note that file:content of asset has 's3TransientStore' in its digest value (see attached json.html)
• note that the blob does not appear in the nuxeo.s3storage.bucket

For the record, this behavior is not happening on 10.10 due to usage of s3DirectUploadBlobProviderSource and s3DirectUploadBlobProviderDestination introduced by https://github.com/nuxeo/marketplace-amazon-s3/commit/2f7102d239a90d7cdf3fbfb9097d2042768d21c8