fix: crash if items were not objects

Author: farfromrefug

src/collectionview/index-common.ts

@@ -251,7 +251,7 @@ export abstract class CollectionViewBase extends View implements CollectionViewD
         if (view) {
             // we check old bindingContext to see if properties disappeared.
             // if so we set them to null for the View to update
-            if (view.bindingContext && view.bindingContext !== context) {
+            if (view.bindingContext && view.bindingContext !== context && typeof context === 'object') {
                 Object.keys(view.bindingContext).forEach((k) => {
                     if (!context.hasOwnProperty(k)) {
                         context[k] = null;