PLUGINS-6307 fixed warning message

Author: meteor-ec

lib/ecwid_catalog_entry.php

@@ -93,13 +93,11 @@ public function get_seo_link( $baseUrl = '' ) {
 				$url .= '/';
 			}
 
-			preg_match( '!([^\/]+-[p|c][0-9]+)$!', $this->_data->url, $slug );
-
-			if( ! empty( $slug[1] ) ) {
-				$url .= $slug[1];
-			} else {
-				$url .= $this->_linkify( $this->_data->name ) . '-' . $this->_link_prefix . $this->_data->id;
-			}
+            if ( ! empty( $this->_data->url ) && preg_match( '!([^\/]+-[p|c][0-9]+)$!', $this->_data->url, $slug)) {
+                $url .= $slug[1];
+            } else {
+                $url .= $this->_linkify($this->_data->name) . '-' . $this->_link_prefix . $this->_data->id;
+            }
 
 			if ( ! empty( $query ) ) {
 				$url .= '/?' . $query;