Fix typo

Fixes: d294cda ("Depend on the nbd module being loaded")

Author: yoe

systemd/nbd@.service.tmpl

@@ -4,7 +4,7 @@ Documentation=man:nbd-client
 PartOf=nbd.service
 Before=dev-%i.device
 Before=remote-fs-pre.target
-Requirs=modprobe@nbd.service
+Requires=modprobe@nbd.service
 After=network-online.target
 After=modprobe@nbd.service
 Conflicts=shutdown.target