Bugfix: Spaces need to be deleted before cron save, because they are IGNORED...

Bugfix: Spaces need to be deleted before cron save, because they are IGNORED on validation but lead to a non-functional cron.
Storing minute / hour / etc. values like "1, 23, 26" (with spaces) is allowed in validation and interface but leads to a BLOCKED crontab file and to non-functional crons of the whole web user.