Fix test test_secrets_in_env_variables , Failing due to wrong keys comparison

[paraggit]

As per the comment in BZ: https://ibm.biz/BdGBA6 , No need to look for the keys token and mon_host in the enc var.
Existing test looking for those keys and hits an assert condition.

RUN_ID: https://ibm.biz/BdGBuc

Error Message:

E                       AssertionError: Key: dmcrypt-key is not expected in securityKeyRef, may be secrutiy breach please check
E                       assert 'dmcrypt-key' in {'ceph-secret', 'ceph-username', 'fsid', 'mon_host', 'mon_initial_members', 'token'}