Don't exit with a non-zero value in case no new devices were discovered, as non-zero codes are considered failed jobs for most cron implementations and produce logs like the following (in Debian):
```
cron.info CRON[963890]: (CRON) error (grandchild #963892 failed with exit status 5)
```
DO NOT DELETE THIS TEXT
#### Please note
> Please read this information carefully. You can run `./scripts/pre-commit.php` to check your code before submitting.
- [X] Have you followed our [code guidelines?](http://docs.librenms.org/Developing/Code-Guidelines/)
#### Testers
If you would like to test this pull request then please run: `./scripts/github-apply <pr_id>`, i.e `./scripts/github-apply 5926`
