Fix package script for supporting Win XP
Fix package script for supporting Win XP

`dbghelp.dll` is required to run on Win XP. Added it to package
script.

Fixed #4181

nwjs/nw.js,kurainooni/nw.js,nwjs/nw.js,kurainooni/nw.js,kurainooni/nw.js,kurainooni/nw.js,kurainooni/nw.js,nwjs/nw.js,nwjs/nw.js,kurainooni/nw.js,kurainooni/nw.js,nwjs/nw.js,nwjs/nw.js