The restore.action should recognise if invalid zip file is provided instead of throwing a NPE.

This was working on 2.3 stable yet a change made since effected it's functionality and not handling a 'null' exportType when not found in the temporarily unzipped file -> Properties object.

public static String getExportTypeFromExportZip(File exportZip, boolean cleanup) throws ImportExportException

........
exportType = descriptorProperties.getProperty(PROP_EXPORT_TYPE);