Fixing the if statement which checks for Cloud KMS Admins (#38)
Fixing the if statement which checks for Cloud KMS Admins (#38)

Fix for the following error:
```
  ×  cis-gcp-1.11-iam: [IAM] Ensure that Separation of duties is enforced while assigning KMS related roles to users
     ×  Control Source Code Error inspec-gcp-cis-benchmark-1.1.0/controls/1.11-iam.rb:23
     undefined method `count' for nil:NilClass
```
GoogleCloudPlatform/inspec-gcp-cis-benchmark