webtransport: fix docstring comment for getCurrentBucketStartTime

Signed-off-by: linchizhen <jiayanbing@yeah.net>

p2p/transport/webtransport/cert_manager.go

@@ -71,7 +71,7 @@ func newCertManager(hostKey ic.PrivKey, clock clock.Clock) (*certManager, error)
 	return m, nil
 }
 
-// getCurrentTimeBucket returns the canonical start time of the given time as
+// getCurrentBucketStartTime returns the canonical start time of the given time as
 // bucketed by ranges of certValidity since unix epoch (plus an offset). This
 // lets you get the same time ranges across reboots without having to persist
 // state.