refactor(test/clouddriver): Cleanup impractical tests in TrafficGuard…

…Spec

The API call 'front50Service.get(application)' mocked/stubbed to return null value is not realistic, because if the application is not available , then this API would throw a 404 HTTP error and thats already handled in the same class: https://github.com/spinnaker/orca/blob/7e923cc05af0f66b952245722aa69c667f685c5c/orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/utils/TrafficGuardSpec.groovy#L464.

and hence this test is cleaned up.

orca-clouddriver/src/test/groovy/com/netflix/spinnaker/orca/clouddriver/utils/TrafficGuardSpec.groovy

@@ -446,15 +446,6 @@ class TrafficGuardSpec extends Specification {
     "app"   | "test"  | null       | "zz"        | "test"       | "us-east-1"   || false // different detail
   }
 
-  void "hasDisableLock returns false on missing applications"() {
-    when:
-    boolean result = trafficGuard.hasDisableLock(new Moniker(app: "app", cluster: "app"), "test", location)
-
-    then:
-    result == false
-    1 * front50Service.get("app") >> null
-  }
-
   void "hasDisableLock returns false on applications with no guards configured"() {
     when:
     boolean result = trafficGuard.hasDisableLock(new Moniker(app: "app", cluster: "app"), "test", location)