Clarify the fetch-crl-boot service

Co-authored-by: Matyas Selmeci <[email protected]>

Author: brianhlin

docs/common/ca.md

@@ -219,7 +219,7 @@ To modify the times that `fetch-crl-cron` runs, edit `/etc/cron.d/fetch-crl`.
 |:----------|:-----------------------------|:-------------------------------------------|
 | Fetch CRL | `fetch-crl.timer` (EL8-only) | Runs `fetch-crl` every 6 hours and on boot |
 |           | `fetch-crl-cron` (EL7-only)  | Runs `fetch-crl` every 6 hours             |
-|           | `fetch-crl-boot` (EL7-only)  | Runs `fetch-crl` immediately               |
+|           | `fetch-crl-boot` (EL7-only)  | Runs `fetch-crl` immediately and on boot              |
 
 Start the services in the order listed and stop them in reverse order. As a reminder, here are common service commands (all run as `root`):