MOBILE-2795 data: Fix error modal displayed twice when adding an empty entry

src/addon/mod/data/pages/edit/edit.ts

@@ -276,10 +276,7 @@ export class AddonModDataEditPage {
             });
         }).catch((error) => {
             this.domUtils.showErrorModalDefault(error, 'Cannot edit entry', true);
-
-            return Promise.reject(null);
         });
-
     }
 
     /**