isset() vs !empty(), when the legacy code stores false.... it eventually...

isset() vs !empty(), when the legacy code stores false.... it eventually translates into a missing entry after save, before save, it's set with false....

(cherry picked from commit 3a96c1dd)
(cherry picked from commit e77d568e)

src/etc/inc/plugins.inc.d/if_ipsec.inc

@@ -44,7 +44,7 @@ function if_ipsec_services()
 
     $services = array();
 
-    if (isset($config['ipsec']['enable']) || isset($config['ipsec']['client']['enable'])) {
+    if (!empty($config['ipsec']['enable']) || !empty($config['ipsec']['client']['enable'])) {
         $pconfig = array();
         $pconfig['name'] = 'strongswan';
         $pconfig['description'] = gettext('IPsec VPN');
@@ -68,17 +68,17 @@ function if_ipsec_interfaces()
 
     if (isset($config['ipsec']['phase1']) && isset($config['ipsec']['phase2'])) {
         foreach ($config['ipsec']['phase1'] as $ph1ent) {
-            if (isset($ph1ent['disabled'])) {
+            if (!empty($ph1ent['disabled'])) {
                 continue;
             }
 
             foreach ($config['ipsec']['phase2'] as $ph2ent) {
-                if (isset($ph2ent['disabled']) || $ph1ent['ikeid'] != $ph2ent['ikeid']) {
+                if (!empty($ph2ent['disabled']) || $ph1ent['ikeid'] != $ph2ent['ikeid']) {
                     continue;
                 }
 
-                if ((isset($ph2ent['mobile']) && !isset($config['ipsec']['client']['enable'])) ||
-                    !isset($config['ipsec']['enable'])) {
+                if ((!empty($ph2ent['mobile']) && empty($config['ipsec']['client']['enable'])) ||
+                    empty($config['ipsec']['enable'])) {
                     continue;
                 }
 

src/etc/inc/plugins.inc.d/if_openvpn.inc

@@ -47,7 +47,7 @@ function if_openvpn_services()
     foreach (array('server', 'client') as $mode) {
         if (isset($config['openvpn']["openvpn-{$mode}"])) {
             foreach ($config['openvpn']["openvpn-{$mode}"] as $setting) {
-                if (!isset($setting['disable'])) {
+                if (empty($setting['disable'])) {
                     $pconfig = array();
                     $pconfig['description'] = "OpenVPN {$mode}: " . htmlspecialchars($setting['description']);
                     $pconfig['pidfile'] = "/var/run/openvpn_{$mode}{$setting['vpnid']}.pid";
@@ -75,7 +75,7 @@ function if_openvpn_interfaces()
     foreach (array('server', 'client') as $mode) {
         if (isset($config['openvpn']["openvpn-{$mode}"])) {
             foreach ($config['openvpn']["openvpn-{$mode}"] as &$settings) {
-                if (!isset($settings['disable'])) {
+                if (empty($settings['disable'])) {
                     $oic = array('enable' => true);
                     $oic['if'] = 'openvpn';
                     $oic['descr'] = 'OpenVPN';