When PXE Localboot Default is deleted, causes nil error when cancelling build
The following error is generated when TFTP PXELinux templates are deployed, but no template can be resolved:
Failed to generate PXELinux template: undefined method `template' for nil:NilClass
This can happen when the built in "PXE Localboot Default" template is removed. A better error message would be useful, and maybe a setting to allow the user to select another behaviour or template.