update README.md

scripts/bash/README.md

@@ -74,3 +74,14 @@ vps-b280dcff.vps.ovh.net  vps-value-1-2-40    2019v1  40  2048
 vps-f31d3392.vps.ovh.net  vps-starter-1-2-20  2019v1  20  2048
 ```
 
+5. If credentials are revoked
+
+```bash
+./ovh-bash get vps
+{
+  "class": "Client::Forbidden",
+  "message": "This credential is not valid",
+  "httpCode": "403 Forbidden",
+  "errorCode": "INVALID_CREDENTIAL"
+}
+```