Update printer.js
Update printer.js

This is to allow automatic testing of pdf generation via it hash sum. Having a non fixed value for creation date will make it impossible to grant a constant hash for the same pdf file.
dennisrjohn/pdfmake,dennisrjohn/pdfmake,TW-QEN/pdfmake,TW-QEN/pdfmake,bavellone/pdfmake,bavellone/pdfmake