fix: regex match for cronjob cleanup

[shreddedbacon]

This fixes the regex for cronjob cleanup so that it will remove cronjobs that don't exist.

Previously if I had a cronjob named drush cron and then renamed it to be drush cron different. The current regex check would mean that both of these cronjobs would remain. drush cron would not get cleaned up, when it should.

current

re='\<cronjob-cli-drush-cron\>'
text=cronjob-cli-drush-cron
$ if [[ "$text" =~ $re ]]; then echo match; fi
match
text=cronjob-cli-drush-cron-different
$ if [[ "$text" =~ $re ]]; then echo match; fi
match

fixed

re='\<^cronjob-cli-drush-cron$\>'
text=cronjob-cli-drush-cron
$ if [[ "$text" =~ $re ]]; then echo match; fi
match
text=cronjob-cli-drush-cron-different
$ if [[ "$text" =~ $re ]]; then echo match; fi

[tobybellwood]

LGTM