Update cron.md (#6229)

The original path reference makes no sense now that Drush is site-specific.

docs/cron.md

@@ -14,7 +14,7 @@ You should set up crontab to run your cron tasks as the same user that runs the
 
     sudo crontab -u www-data -e
 
-You might need to edit the crontab entry shown above slightly for your particular setup; for example, if you have installed Drush to some directory other than /usr/local/drush, then you will need to adjust the path to drush appropriately. We'll break down the meaning of each section of the crontab entry in the documentation that continues below.
+You might need to edit the crontab entry shown above slightly for your particular setup; we'll break down the meaning of each section of the crontab entry in the documentation that continues below.
 
 Setting the schedule
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