Bridge interface input validation fix. Issue #12866

src/usr/local/www/interfaces_bridge_edit.php

@@ -187,7 +187,7 @@ function is_aoadv_used($pconfig) {
 	if (is_array($_POST['members']) && is_array($config['captiveportal'])) {
 		foreach ($_POST['members'] as $member) {
 			foreach ($config['captiveportal'] as $cp) {
-				if (in_array($member, explode(',', $cp['interface']))) {
+				if (isset($cp['enable']) && in_array($member, explode(',', $cp['interface']))) {
 					$input_errors[] = sprintf(gettext('The interface (%s) is part of ' .
 						'the Captive Portal and cannot be part of the bridge. ' .
 						'Remove the interface to continue.'), $ifacelist[$cpint]);