cron: Work even without initial crontab

Fixes #2165.

library/cron

@@ -333,12 +333,9 @@ def main():
             os.unlink(backupfile)
             module.exit_json(changed=changed,cron_file=cron_file,state=state)
 
-    if (rc != 0):
-        module.fail_json(msg=err)
-
     if changed:
         # If the file is empty - remove it
-        if rm:
+        if rm and cron_file:
             remove_job_file(cron_file)
         else:
             if backup: