[js][plotter] Fix do not show first option for dataformat when no selection was done. Closes #154

conda/js/src/components/plotter/PlotterEditor.jsx

@@ -257,6 +257,12 @@ const mapStateToProps = (state, ownProps) => {
 		plotDfNames: Selectors.dataformatGet(state).map(df => df.name).filter(df => df.startsWith('plot/')),
 		data: plotters[ownProps.index] || getValidObj(),
 	};
+
+	if(obj.data.contents.dataformat === "")
+	{
+		obj.plotDfNames.unshift("-- select an option --")
+	};
+
 	return obj;
 };