Inaccurate warning about LDAP bind password being in `ldap.yml`

[coffee-squirrel]

Describe the bug
As of 1.0.72, and including 1.0.73, we see output like the following with every cf-mgmt command in our pipeline (delete-orgs, update-org-users, update-space-users, etc.):

2023/11/20 16:57:34 W1120 16:57:34.799654 20 yaml_config.go:542] Ldap bind password should be removed from ldap.yml as this will be deprecated in a future release.  Use --ldap-password flag instead.

This output does not show up in 1.0.71 or older.

We pass in the LDAP password via the LDAP_PASSWORD environment variable, and don't have anything in our ldap.yml for that value.

Probably related to #449, which appears to have touched some LDAP-related stuff.

To Reproduce
Steps to reproduce the behavior:

1. Have a working LDAP config (LDAP_PASSWORD env var, the rest in ldap.yml) and have LOG_LEVEL=info.
2. Run a command (e.g. cf-mgmt update-space-users) using cf-mgmt 1.0.71 or older and note the warning doesn't appear
3. Run a command (e.g. cf-mgmt update-space-users) using cf-mgmt 1.0.72 or newer and note the warning appears

Expected behavior
The warning about having the LDAP bind password in ldap.yml should only occur if the property actually exists in ldap.yml.

[cf-gitbot]

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