replication: avoid passing removed storages to target

replication: avoid passing removed storages to target

After removing a storage, replication states can still contain
references to it, even if no volume references it anymore.

If a storage does not exist in the storage configuration, the
replication target runs into an error when preparing the job locally.
This error prevents both running and removing the replication job. Fix
it by not passing the invalid storage ID in the first place.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>