Remove obsolete dnssec-enable option (#5928)

Author: Thom Pol

install/tpl/named.conf.options.master

@@ -18,11 +18,10 @@ options {
 	// If BIND logs error messages about the root key being expired,
 	// you will need to update your keys.  See https://www.isc.org/bind-keys
 	//========================================================================
-	dnssec-enable yes;
 	dnssec-validation yes;
 
 	version "unknown";
-	
+
 	allow-transfer {none;};
 
 	auth-nxdomain no;    # conform to RFC1035