downgrade model-not-found to a warning, default to sqk005 transition probabilities
downgrade model-not-found to a warning, default to sqk005 transition probabilities

mateidavid/nanopolish,mateidavid/nanopolish,jts/nanopolish,jts/nanopolish,jts/nanopolish,mateidavid/nanopolish,jts/nanopolish,jts/nanopolish,mateidavid/nanopolish,mateidavid/nanopolish