Fixing credential lookup for fe proxy and vault (#2361)

roles/vault/defaults/main.yml

@@ -166,7 +166,7 @@ vault_pki_mounts:
           organization: "system:node-proxier"
       - name: front-proxy-client
         group: k8s-cluster
-        password: "{{ lookup('password', 'credentials/vault/kube-proxy length=15') }}"
+        password: "{{ lookup('password', inventory_dir + '/credentials/vault/kube-proxy length=15') }}"
         policy_rules: default
         role_options:
           allow_any_name: true