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/handler.go

@@ -470,9 +470,13 @@ func (h *apiHandlers) PostCompose(ctx echo.Context) error {
 				if err != nil {
 					return HTTPError(ErrorJSONUnMarshallingError)
 				}
+				rgLocation := ""
+				if azureUploadOptions.Location != nil {
+					rgLocation = *azureUploadOptions.Location
+				}
 				t := target.NewAzureImageTarget(&target.AzureImageTargetOptions{
 					TenantID:       azureUploadOptions.TenantId,
-					Location:       azureUploadOptions.Location,
+					Location:       rgLocation,
 					SubscriptionID: azureUploadOptions.SubscriptionId,
 					ResourceGroup:  azureUploadOptions.ResourceGroup,
 				})