downloadGemStone force flag does not affect unzip

[marcfreiheit]

Hey,

during installation of your DevKit I've found that small bug. When running your script with the force flag (downloadGemStone -f ...) I expect to overwrite existing files. But I get a prompt how to handle the existing directory. I would suggest something similar to

if [ "${force}" = "true" ] ; then
  unzip_overwrite=-o
fi
unzip -q -d $unzip_overwrite "$GS_SHARED_DOWNLOADS/products" $dl_gss_file 

Affected line of code: https://github.com/GsDevKit/GsDevKit_home/blob/2a6a51f76843b30d6bcc3cf903c444f3d7f9890c/bin/downloadGemStone#L161