test/api: don't provide Resource Group Location when testing Azure

Let's default to not providing the Resource Group Location when testing
Cloud API with Azure and leave it up to the implementation to determine
the correct location to use.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

test/cases/api/azure.sh

@@ -94,7 +94,6 @@ function createReqFile() {
       "tenant_id": "${AZURE_TENANT_ID}",
       "subscription_id": "${AZURE_SUBSCRIPTION_ID}",
       "resource_group": "${AZURE_RESOURCE_GROUP}",
-      "location": "${AZURE_LOCATION}",
       "image_name": "${AZURE_IMAGE_NAME}"
     }
   }