use proxy in sanity check of custom easyblock to install OpenSSL wrapper

[trz42]

One sanity check that tries to connect to github.com fails, when OpenSSL-1.1.eb is built on a machine without direct access to the internet.

This PR resolves the issue by adding the parameter -proxy when openssl is run. It only does so when the environment variable https_proxy is defined. urlparse from urllib.parse is used to determine the host and port of the proxy setting which could be a URL such as https://localproxy.cluster:4321/.

The change has been tested for environments with and without proxies, ie, direct access to the internet (environment variable https_proxy not set) and no direct access to the internet (environment variable https_proxy set). See comments NorESSI/software-layer#100 (comment), NorESSI/software-layer#100 (comment) (both with direct access to internet) and NorESSI/software-layer#100 (comment) (no direct access to internet, original build failed, see NorESSI/software-layer#100 (comment)). The changed easyblock was used via --include-easyblocks=path/to/openssl_wrapper.py.

[trz42]

Just updated the PR @akesandgren @jfgrimm ... apologies for the long delay.

[boegel]

Test report by @boegel

Overview of tested easyconfigs (in order)

• SUCCESS OpenSSL-1.0.eb
• SUCCESS OpenSSL-1.1.eb

Build succeeded for 2 out of 2 (2 easyconfigs in total)
node3110.skitty.os - Linux RHEL 8.8, x86_64, Intel(R) Xeon(R) Gold 6140 CPU @ 2.30GHz, Python 3.6.8
See https://gist.github.com/boegel/b32c5a59a4e2d4115dad1995a823acad for a full test report.

[boegel]

lgtm, also tested with OpenSSL/3 wrapper from easybuilders/easybuild-easyconfigs#19623