Define http proxy variables in Dockerfile before using them

LABEL maintainer="searx <https://github.com/asciimoo/searx>"

LABEL description="A privacy-respecting, hackable metasearch engine."

ENV BASE_URL=False IMAGE_PROXY=False

ENV BASE_URL=False IMAGE_PROXY=False HTTP_PROXY_URL= HTTPS_PROXY_URL=

EXPOSE 8888

WORKDIR /usr/local/searx

CMD ["/sbin/tini","--","/usr/local/searx/run.sh"]