Describe the bug

When a file or folder is shared with a local user, this user receives a notification.
The same should happen with a remote user, receiving a federated share.

Steps to reproduce

Setup two machines with e.g.

env OCIS_DNSNAME=cat-7rc3-DATE OCIS_VERSION=v7.0.0-rc.3 ./deploy_ocis_bare_metal.sh
env OCIS_DNSNAME=elf-7rc3-DATE OCIS_VERSION=v7.0.0-rc.3 ./deploy_ocis_bare_metal.sh

mutually register the machines in their ocmproviders.json; service ocis restart

Alice creates a folder and uploads an mp4 file there.
Alice shares the folder with local user bob and with external user carol with edit permission.

Bob receives a notification. OK
Carol does not get any notification. BAD.

Expected behavior

Actual behavior

Setup

Please describe how you started the server and provide a list of relevant environment variables or configuration files.

OCIS_XXX=somevalue
OCIS_YYY=somevalue
PROXY_XXX=somevalue

Additional context

Add any other context about the problem here.

@hodyroff fyi.