increase icon cache ttl to 3 days, remove pruned message when no icon pruned

internal/api/v1/favicon/cache.go

@@ -24,7 +24,7 @@ var (
 )
 
 const (
-	iconCacheTTL    = 24 * time.Hour
+	iconCacheTTL    = 3 * 24 * time.Hour
 	cleanUpInterval = time.Hour
 )
 
@@ -77,7 +77,9 @@ func pruneExpiredIconCache() {
 			nPruned++
 		}
 	}
+	if nPruned > 0 {
 		logging.Info().Int("pruned", nPruned).Msg("pruned expired icon cache")
+	}
 }
 
 func routeKey(r route.HTTPRoute) string {