6a5e0f9 introduces regression that breaks Vault module for salt masterless

[ghost]

Description of Issue/Question

6a5e0f9 introduces a regression that breaks the Vault module for salt masterless.

Since 6a5e0f9, we get the following error message running salt-call --local state.apply:

    [CRITICAL] Rendering SLS 'foo' failed, render error:
    Problem running salt function in Jinja template: [Errno 2] No such file or directory: '/etc/salt/pki/minion/minion.pem'; line 9

    ---
    [...]
        foo:
          - "{{ salt.sdb.get('sdb://my-vault/secret/foo?value') }}"    <======================
    ---

Setup

We use Packer to generate machine images, with Salt masterless for configuration management. This change prevents us from being able to build new images because it breaks the Vault module for Salt masterless.