Add 'host/' prefix if missing instead of raising error

[orenbm]

Currently, if the customer forgot to add the host/ prefix to CONJUR_AUTHN_LOGIN we raise the error CONJUR_AUTHN_LOGIN %s must start with 'host/'.

We might do better by adding the prefix by ourselves instead of raising an error. However, we need to further look into it before we make such a change. What if the customer tries to use a user (which is not supported)? in this case we will add host/ to it and it may fail because of some other unexpected behaviour.

We should look into this and decide if this is a good UX enhancement.

DoD:

• Prefix is added in case it is not present, or
• A comment is written for why we don't do it

[jtuttle]

I think I would prefer we continue to raise an error here. It's more explicit and doesn't involve any behind-the-scenes modifications.