Theme: Do not show "Edit on GitHub" on search.html.

Right now is the only page generated by the theme, if more pages
are added into the future they should be included in the blacklist
in the breadcrumbs.html file.

_includes/breadcrumbs.html

@@ -16,9 +16,9 @@
       {%- endif %}
     {%- endif %}
     <li class="wy-breadcrumbs-aside">
-      {%- unless site.edit_on_github == false %}
+      {%- if site.edit_on_github != false and page and page.name != "search.html" %}
         <a href="{{ site.repo_url | url }}/blob/master/{%- if site.github_docs_folder %}docs/{% endif %}{{ page.path }}" class="icon icon-github" target="_blank"> Edit on GitHub</a>
-      {%- endunless %}
+      {%- endif %}
     </li>
   </ul>