op-mode: T6503: "restart ssh" command not working

Commit e5af1f090 ("ssh: T6192: allow binding to multiple VRF instances")
switched the systemd unit file from ssh.service to ssh@*.service, this change
was not reflected in the "restart ssh" op-mode command.

(cherry picked from commit 059eb3a137a75d502632174cc028b81f49152782)