Correctly close the context action mode when deleting an account.

src/com/fsck/k9/activity/Accounts.java

@@ -1027,6 +1027,7 @@ public class Accounts extends K9ListActivity implements OnItemClickListener {
                         .deleteAccount(realAccount);
                         K9.setServicesEnabled(Accounts.this);
                         refresh();
+                        mActionMode.finish();
                     }
                 }
             });