Issue 3758 - Removed Opera Extensions related logic

sitescripts/extensions/template/nightlies.html

 <!--
   - This file is part of the Adblock Plus web scripts,
   - Copyright (C) 2006-2016 Eyeo GmbH
   -
   - Adblock Plus is free software: you can redistribute it and/or modify
   - it under the terms of the GNU General Public License version 3 as
   - published by the Free Software Foundation.
   -
   - Adblock Plus is distributed in the hope that it will be useful,
   - but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 14 matching lines @@
   properly.
 
   Use them at your own risk, see <a href="https://adblockplus.org/en/development-builds">development builds introduction</a> for more information.
 
   {%if config.galleryID or config.downloadPage -%}
   Latest <em>stable {{config.name}} release</em> can be downloaded from
   {% if config.type == 'gecko' and config.galleryID -%}
     <a href="https://addons.mozilla.org/addon/{{config.galleryID}}/">Mozilla Add-ons</a>
   {%- elif config.type == 'chrome' and config.galleryID -%}
     <a href="https://chrome.google.com/webstore/detail/{{config.galleryID}}">Chrome Web Store</a>
-  {%- elif config.type == 'opera' and config.galleryID -%}
-    <a href="https://addons.opera.com/en/extensions/details/{{config.galleryID}}/">Opera Add-ons</a>
   {%- else %}
     <a href="https://adblockplus.org{{config.downloadPage}}">its installation page</a>
   {%- endif -%}
   .
   {%- endif %}
 
   {%- if config.type == 'chrome' and config.experimental -%}
     <br /><br />
     <em>Note</em>: The builds in this directory use experimental Google Chrome API.
     To install them you have to enable support for these APIs by going to
@@ skipping 13 matching lines @@
     {%- endif %}
   </td>
   <td>{{link.mtime|formattime}}</td>
   <td>{{link.size|bytes}}</td>
 </tr>
 {%- endfor %}
 </table>
 <hr />
 </body>
 </html>