dns/rfc2136: probable fix for #3187

This could be more elegant in some other format that is allowed but
someone else will have to open a reasonable PR about it.  I don't
trust the number change alone in the PR as bind said it would try
to "unbreak" it again breaking the plugin if we would...

dns/rfc2136/Makefile

@@ -1,6 +1,5 @@
 PLUGIN_NAME=		rfc2136
-PLUGIN_VERSION=		1.6
-PLUGIN_REVISION=	3
+PLUGIN_VERSION=		1.7
 PLUGIN_COMMENT=		RFC-2136 Support
 PLUGIN_MAINTAINER=	franco@opnsense.org
 PLUGIN_DEPENDS=		bind-tools

dns/rfc2136/src/etc/inc/plugins.inc.d/rfc2136.inc

@@ -125,9 +125,10 @@ function rfc2136_configure_do($verbose = false, $int = '', $updatehost = '', $fo
            but nsupdate insists on having both */
         $fd = fopen("/var/etc/K{$i}{$keyname}+157+00000.private", "w");
         $privkey = <<<EOD
-Private-key-format: v1.2
-Algorithm: 157 (HMAC)
-Key: {$dnsupdate['keydata']}
+key "{$keyname}" {
+	algorithm hmac-md5;
+	secret "{$dnsupdate['keydata']}";
+};
 
 EOD;
         fwrite($fd, $privkey);