Diffusion: Fix broken repository view

Summary:
The readonly property is capitalized, but the property defined
in AphrontFormTypeaheadControl isn't.

Follows-up 586296b3d192.

Test Plan: Visit any diffusion repository main page.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Differential Revision: https://we.phorge.it/D26210

src/view/form/control/AphrontFormTypeaheadControl.php

···
 
   private $hardpointID;
   private $placeholder;
-  private $readonly;
+  private $readOnly;
 
   public function setHardpointID($hardpoint_id) {
     $this->hardpointID = $hardpoint_id;