(hasync) add dns resolver to sync, service restart not included, probably...

(hasync) add dns resolver to sync, service restart not included, probably needs a seperate page at some point. closes https://github.com/opnsense/core/issues/923

src/etc/rc.filter_synchronize

@@ -291,6 +291,7 @@ if (isset($config['hasync']) && is_array($config['hasync'])) {
     $section_cnf['synchronizeusers'] = 'system.user,system.group';
     $section_cnf['synchronizeauthservers'] = 'system.authserver';
     $section_cnf['synchronizednsforwarder'] = 'dnsmasq';
+    $section_cnf['synchronizednsresolver'] = 'unbound';
     $section_cnf['synchronizeschedules'] = 'schedules';
     $section_cnf['synchronizeshaper'] = 'OPNsense.TrafficShaper';
     $section_cnf['synchronizecaptiveportal'] = 'OPNsense.captiveportal';

src/www/system_hasync.php

@@ -39,7 +39,7 @@ $checkbox_names = array('pfsyncenabled', 'synchronizeusers', 'synchronizeauthser
                         'synchronizerules', 'synchronizeschedules', 'synchronizealiases', 'synchronizenat',
                         'synchronizeipsec', 'synchronizeopenvpn', 'synchronizedhcpd', 'synchronizewol',
                         'synchronizestaticroutes', 'synchronizelb', 'synchronizevirtualip',
-                        'synchronizednsforwarder', 'synchronizeshaper', 'synchronizecaptiveportal'
+                        'synchronizednsforwarder','synchronizednsresolver', 'synchronizeshaper', 'synchronizecaptiveportal'
 );
 
 
@@ -328,6 +328,15 @@ include("head.inc");
                     </div>
                   </td>
                 </tr>
+                <tr>
+                  <td><a id="help_for_synchronizednsresolver" href="#" class="showhelp"><i class="fa fa-info-circle"></i></a> <?=gettext('DNS Resolver') ?></td>
+                  <td>
+                    <input type="checkbox" name="synchronizednsresolver" value="on" <?=!empty($pconfig['synchronizednsresolver']) ? "checked=\"checked\"" :"";?> />
+                    <div class="hidden" for="help_for_synchronizednsresolver">
+                      <?=gettext('Automatically sync the DNS Resolver configuration to the other HA host when changes are made.') ?>
+                    </div>
+                  </td>
+                </tr>
                 <tr>
                   <td><a id="help_for_synchronizeshaper" href="#" class="showhelp"><i class="fa fa-info-circle"></i></a> <?=gettext('Traffic Shaper') ?></td>
                   <td>