cloudapi: make location optional in Azure Upload Options

Providing the `location` is no longer required for Azure Upload Options.
If it is not provided, the implementation determines the location from
the provided Resource Group. This will make the API nicer for any
client, since they won't need to provide redundant information.

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

internal/cloudapi/v2/openapi.v2.yml

@@ -917,7 +917,6 @@ components:
         - tenant_id
         - subscription_id
         - resource_group
-        - location
       properties:
         tenant_id:
           type: string
@@ -940,9 +939,10 @@ components:
           type: string
           example: 'westeurope'
           description: |
-            Location where the image should be uploaded and registered.
+            Location of the provided resource_group, where the image should be uploaded and registered.
             How to list all locations:
             https://docs.microsoft.com/en-us/cli/azure/account?view=azure-cli-latest#az_account_list_locations'
+            If the location is not specified, it is deducted from the provided resource_group.
         image_name:
           type: string
           example: 'my-image'