Logger might be broken in N2.Persistence.Serialization.Importer

Cristian, can you investigate? I'm getting a warning that logger is never assigned

namespace N2.Persistence.Serialization
{
    public class Importer
    {
        private Engine.Logger<Importer> logger; // TODO: Figure out how/where this gets initialized.
...

https://github.com/n2cms/n2cms/blob/6296427a9cf103a657e2742d54b97d68f11edc30/src/Framework/N2/Persistence/Serialization/Importer.cs

It is later used in a few places such as...

...
                logger.ErrorFormat("Option {0} isn't supported", options);
                throw new NotImplementedException("This option isn't implemented, sorry.");
            }
...

n2cms / n2cms

Logger might be broken in N2.Persistence.Serialization.Importer #184