Support loading "com.gs.security.properties-file" from url
When security is enabled, we load the config from -Dcom.gs.security.properties-file, and if not specified, we use the default security packaged with the product.
This is very cumbersome in docker/k8s, since the custom file is not part of the image, so the only option for now is extending the image...
As a quick workaround, suggest we support loading "com.gs.security.properties-file" from url as well, so user can put them in external resource. This also affects spring-security-config-location