PKGget translation fix

Forum member don570 reported some text in PKGget not translated:

https://forum.puppylinux.com/viewtopic.php?t=14323

I found the cause, in /usr/local/petget/installpkg.sh, see commit:

https://github.com/bkauler/woofq/commit/7246004935212b0e070d778d2f4d556431980e08

I also changed /usr/bin/pupmessage to run gxmessage instead of xmessage, as this was another translation problem reported by don570. See commit:

https://github.com/bkauler/woofq/commit/871ed35b389cbc875ee3e03bc391172847be0ecf    

Tags: easy