Merge pull request #1516 from mailpoet/listings-warning

Emails listing JS warning fix [MAILPOET-1537]

assets/js/src/listing/listing.jsx

@@ -456,9 +456,9 @@ const Listing = React.createClass({
     this.initWithParams(params);
   },
   getItems: function getItems() {
-    if (this.isComponentMounted) {
-      this.setState({ loading: true });
+    if (!this.isComponentMounted) return;
 
+    this.setState({ loading: true });
     this.clearSelection();
 
     MailPoet.Ajax.post({
@@ -476,8 +476,10 @@ const Listing = React.createClass({
         sort_order: this.state.sort_order,
       },
     }).always(() => {
+      if (!this.isComponentMounted) return;
       this.setState({ loading: false });
     }).done((response) => {
+      if (!this.isComponentMounted) return;
       this.setState({
         items: response.data || [],
         filters: response.meta.filters || {},
@@ -504,7 +506,6 @@ const Listing = React.createClass({
         );
       }
     });
-    }
   },
   handleRestoreItem: function handleRestoreItem(id) {
     this.setState({