TBR: devtools/jiri-test: always use -with-passphrase=false in prod service test.

This way we can test this in a terminal environment.

PresubmitTest: none
Change-Id: I173da710830d9481056be8bec214032c46bbe836
diff --git a/jiri-test/internal/test/prod.go b/jiri-test/internal/test/prod.go
index 7dd9b19..0daa78a 100644
--- a/jiri-test/internal/test/prod.go
+++ b/jiri-test/internal/test/prod.go
@@ -219,7 +219,7 @@
 	s := jirix.NewSeq()
 	dir := filepath.Join(tmpdir, "credentials")
 	bin := filepath.Join(jirix.Root, "release", "go", "bin", "principal")
-	if err := s.Timeout(test.DefaultTimeout).Last(bin, "create", dir, "prod-services-tester"); err != nil {
+	if err := s.Timeout(test.DefaultTimeout).Last(bin, "create", "-with-passphrase=false", dir, "prod-services-tester"); err != nil {
 		fmt.Fprintf(jirix.Stderr(), "principal create failed: %v\n", err)
 		return "", err
 	}