Fix multisite post obj compatibility with ACF v6.3 (#126)

Author: jaakkolehtonen

src/Fields/MultisitePostObject.php

@@ -95,12 +95,13 @@ public function polylang_filter( $args ) {
              * @param mixed   $field     Field.
              * @param integer $post_id   Post ID.
              * @param integer $is_search Is search.
+             * @param boolean $unescape  Unescape.
              *
              * @return string
              */
-            public function get_post_title( $post, $field, $post_id = 0, $is_search = 0 ) {
+            public function get_post_title( $post, $field, $post_id = 0, $is_search = 0, $unescape = false ) {
                 \switch_to_blog( $field['blog_id'] );
-                $title = parent::get_post_title( $post, $field, $post_id, $is_search );
+                $title = parent::get_post_title( $post, $field, $post_id, $is_search, $unescape );
                 \restore_current_blog();
 
                 // return