OCS capabilities returns "undelete" even when trashbin is disabled

[PVince81]

Disable trashbin app then run:
curl http://root:admin@localhost/owncloud/ocs/v1.php/cloud/capabilities

<?xml version="1.0"?>
<ocs>
 <meta>
  <status>ok</status>
  <statuscode>100</statuscode>
  <message/>
 </meta>
 <data>
  <capabilities>
   <files>
    <versioning>1</versioning>
    <bigfilechunking>1</bigfilechunking>
    <undelete>1</undelete>
   </files>
   <core>
    <pollinterval>60</pollinterval>
   </core>
  </capabilities>
  <version>
   <major>7</major>
   <minor>0</minor>
   <micro>3</micro>
   <string>7.0.3</string>
   <edition></edition>
  </version>
 </data>
</ocs>

Expected result: "undelete" should be gone.

Tagging as junior job, the way how "versioning" is set could be used as an example on how to do this properly with "undelete". Because currently "undelete" is hard-coded to true: https://github.com/owncloud/core/blob/master/apps/files/lib/capabilities.php#L18