Merge pull request #2352 from dalf/no_http

## Resources in the documentation

* [Development quickstart](http://searx.github.io/searx/dev/contribution_guide.html)

* [Contribution guide](http://searx.github.io/searx/dev/contribution_guide.html)

* [Development quickstart](https://searx.github.io/searx/dev/contribution_guide.html)

* [Contribution guide](https://searx.github.io/searx/dev/contribution_guide.html)

## Submitting PRs

    CONF="$1"

    # Make sure that there is trailing slash at the end of BASE_URL

    # see http://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Shell-Parameter-Expansion

    # see https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html#Shell-Parameter-Expansion

    export BASE_URL="${BASE_URL%/}/"

    # update settings.yml

If your docs build (``make docs``) shows warnings like this::

   WARNING: dot(1) not found, for better output quality install \

            graphviz from http://www.graphviz.org

            graphviz from https://www.graphviz.org

   ..

   WARNING: LaTeX command 'latex' cannot be run (needed for math \

            display), check the imgmath_latex setting

.. _nginx server configuration:

   https://docs.nginx.com/nginx/admin-guide/web-server/web-server/#setting-up-virtual-servers

.. _nginx beginners guide:

   http://nginx.org/en/docs/beginners_guide.html

   https://nginx.org/en/docs/beginners_guide.html

.. _Getting Started wiki:

   https://www.nginx.com/resources/wiki/start/

.. _uWSGI support from nginx:

  specific instance of searx, a locale can be defined using an ISO language

  code, like ``fr``, ``en``, ``de``.

.. _requests proxies: http://requests.readthedocs.io/en/latest/user/advanced/#proxies

.. _requests proxies: https://requests.readthedocs.io/en/latest/user/advanced/#proxies

.. _PySocks: https://pypi.org/project/PySocks/

``proxies`` :