openvpn/ipsec: properly handle interface deletion artefact

The array was still there, and even though empty evaluated as
being filled with data that requires an interface.

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

@@ -64,8 +64,7 @@ function if_ipsec_interfaces()
 
     $interfaces = array();
 
-    /* add ipsec interfaces */
-    if (isset($config['ipsec']['enable']) || isset($config['ipsec']['client']['enable'])) {
+    if (isset($config['ipsec']['phase1']) && count($config['ipsec']['phase1'])) {
         $oic = array("enable" => true);
         $oic['if'] = 'enc0';
         $oic['descr'] = 'IPsec';

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

@@ -73,8 +73,8 @@ function if_openvpn_interfaces()
 
     $interfaces = array();
 
-    /* add openvpn interfaces */
-    if (isset($config['openvpn']['openvpn-server']) || isset($config['openvpn']['openvpn-client'])) {
+    if ((isset($config['openvpn']['openvpn-server']) && count($config['openvpn']['openvpn-server'])) ||
+        (isset($config['openvpn']['openvpn-client']) && count($config['openvpn']['openvpn-client']))) {
         $oic = array("enable" => true);
         $oic['if'] = "openvpn";
         $oic['descr'] = 'OpenVPN';