PDFsam Basic 3.3.4 fixing Java 9 compatibility

there was a compatibility issue with PDFsam Basic version 3.3.3 (and below) that was preventing it to start with Java 9. We just released PDFsam Basic 3.3.4 and with that everything should be back to normal and work as expected even if you upgrade to Java 9. We also added handy row headers to easily find the index of the added PDF files and the total number of added PDF files.