Updates clair period param (quay#1166)

Co-authored-by: Steven Smith <[email protected]>

Author: stevsmit

modules/config-fields-clair-matcher.adoc

@@ -32,7 +32,7 @@ Defaults to `30m`.
 
 | **.period** | String | Determines how often updates for new security advisories take place.
 
-Defaults to `30m`.
+Defaults to `6h`.
 
 | **.disable_updaters** | Boolean | Whether to run background updates or not.