Merge pull request #1435 from neilgaietto/U4-8822

U4-8822- Fixes Unpublish error with empty RTE

src/Umbraco.Web.UI.Client/src/views/propertyeditors/rte/rte.controller.js

@@ -359,7 +359,8 @@ angular.module("umbraco")
                 //this is instead of doing a watch on the model.value = faster
                 $scope.model.onValueChanged = function (newVal, oldVal) {
                     //update the display val again if it has changed from the server;
-                    tinyMceEditor.setContent(newVal, { format: 'raw' });
+                    //uses an empty string in the editor when the value is null
+                    tinyMceEditor.setContent(newVal || "", { format: 'raw' });
                     //we need to manually fire this event since it is only ever fired based on loading from the DOM, this
                     // is required for our plugins listening to this event to execute
                     tinyMceEditor.fire('LoadContent', null);