Update doc

Author: jiangpengcheng

main.go

@@ -113,8 +113,8 @@ func main() {
 		"The backend config name used for functions&sinks&sources in the same namespace")
 	flag.BoolVar(&secureMetrics, "metrics-secure", true, "If set, the metrics endpoint is served securely via HTTPS."+
 		" Use --metrics-secure=false to use HTTP instead.")
-	flag.BoolVar(&addDefaultAffinity, "add-default-affinity", lookupEnvOrBool("ADD_DEFAULT_AFFINITY", true), "If set, the generated pod will add two default podAntiAffinities:"+
-		" one is make pods prefer to be in different zones (soft rule), and one is make pods must not be scheduled on the same node (hard rule).")
+	flag.BoolVar(&addDefaultAffinity, "add-default-affinity", lookupEnvOrBool("ADD_DEFAULT_AFFINITY", true), "If set, the generated pod will add one default podAntiAffinity:"+
+		" make pods prefer not be scheduled on the same node (soft rule).")
 	flag.Parse()
 
 	ctrl.SetLogger(zap.New(zap.UseDevMode(true)))