registrations rpc with non existing plugin-loader-name should fail

Post request
path - http://localhost:8181/restconf/operations/onem2m-plugin-manager:onem2m-plugin-manager-iotdm-plugin-registrations

body:
{
"input":

}

If plugin-loader-name is some plugin that is not created should return 404 not found. Now it returns 200 OK with body
{
"output": {}
}