Remove dependency to growl

[jaroslawhartman]

Reported by Serghei: https://jhartman.pl/wp-admin/comment.php?action=editcomment&c=778

Hi, Jarek!
After DST change, I’ve tried to do a manual timezone update but it fails, and it logs the following error:
[2018-11-02 11:00:00][ERROR: action.script] ./update.sh: line 3: /usr/local/bin/growlnotify: No such file or directory
I can see that growl is a paid notification system. Maybe it is a good idea to remove this dependency?

Regards,
Serghei

[jaroslawhartman]

Fixed in commit 12aa87c