Merge pull request kubernetes#86830 from aojea/unspecified

clarify apiserver bind-address flag usage

Author: k8s-ci-robot

staging/src/k8s.io/apiserver/pkg/server/options/serving.go

@@ -143,7 +143,7 @@ func (s *SecureServingOptions) AddFlags(fs *pflag.FlagSet) {
 	fs.IPVar(&s.BindAddress, "bind-address", s.BindAddress, ""+
 		"The IP address on which to listen for the --secure-port port. The "+
 		"associated interface(s) must be reachable by the rest of the cluster, and by CLI/web "+
-		"clients. If blank, all interfaces will be used (0.0.0.0 for all IPv4 interfaces and :: for all IPv6 interfaces).")
+		"clients. If blank or an unspecified address (0.0.0.0 or ::), all interfaces will be used.")
 
 	desc := "The port on which to serve HTTPS with authentication and authorization."
 	if s.Required {