Fix chmod on startup *nix when downloaded ExifTool can not be excuted

[qdraw]

Describe the bug

When a user is new with starsky Exiftool is downloaded. there is done a chmod +x for the exiftool but when the rights are not enough this can give issues in the background

To Reproduce
Give the temp folder not enough rights. This only happens when there not enough rights on the temp folder or ./exitfool
[UPDATE] This behavior is produced by a deploy script

Expected behavior
It should work or warn a user that there is action needed

[qdraw]