Adds cancel button to preferred email recipient sheet

App/Browser View/BrowserViewController.swift

@@ -344,6 +344,10 @@ class BrowserViewController: UIViewController
             }))
         }
         
+        actionSheet.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { _ in
+            actionSheet.dismiss(animated: true, completion: nil)
+        }))
+        
         present(actionSheet, animated: true, completion: nil)
     }