Bump vault used in tests

1.4.x is quite old and is no longer maintained.

Bump it to the latest one.

Change-Id: I6f37872bf5b891636c3dede5b30c75acc641e933
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>

tools/setup-vault-env.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -eux
 if [ -z "$(which vault)" ]; then
-    VAULT_VERSION=1.4.2
+    VAULT_VERSION=1.21.2
     SUFFIX=zip
     case `uname -s` in
         Darwin)