The restore_key api-endpoint is tape/drive/{drive}/restore-key.
Since I cannot set the url parameter for the drivename to null or
undefined, when restoring by exported-key, I moved the
added restore_key-api-code to
"create_key aka POST api2/json/config/tape-encryption-keys" and
added an ApiHandler call in the cli's "restore_key" to call
"create_key" in the api.
Signed-off-by: Markus Frank <m.frank@proxmox.com>