Merge branch 'feature/3880_pdf_sharing' into 'develop'

MESSENGER-3880 disallow pdf sharing

See merge request bwmessenger/bundesmessenger/bundesmessenger-ios!46

Riot/Modules/MatrixKit/Controllers/MXKPreviewViewController.m

@@ -77,6 +77,8 @@
             [items removeObjectAtIndex:0];
         }
         self.previewController.navigationItem.rightBarButtonItems = items;
+        // bwi no toolbar items to disallow share files
+        self.previewController.toolbarItems = nil;
     }
 }