fixup! pkg/cluster: Use MS Graph to obtain service principal ID

Clarify error message.

pkg/cluster/serviceprincipal.go

@@ -49,7 +49,7 @@ func (m *manager) clusterSPObjectID(ctx context.Context) error {
 			return false, err
 		}
 		if clusterSPObjectID == nil {
-			return false, fmt.Errorf("appId '%s' not found", spp.ClientID)
+			return false, fmt.Errorf("no service principal found for application ID '%s'", spp.ClientID)
 		}
 		return true, nil
 	}, timeoutCtx.Done())