…enSSL built with SSLv3 support

Make sure you have checked all steps below.

Prerequisite

• Please consider implementing the feature as a hook script or plugin as a first step.
  • pyenv has some powerful support for plugins and hook scripts. Please refer to Authoring plugins for details and try to implement it as a plugin if possible.
• Please consider contributing the patch upstream to rbenv, since we have borrowed most of the code from that project.
  • We occasionally import the changes from rbenv. In general, you can expect changes made in rbenv will be imported to pyenv too, eventually.
  • Generally speaking, we prefer not to make changes in the core in order to keep compatibility with rbenv.
• My PR addresses the following pyenv issue (if any)
  • Closes Python 3.x fails compilation against OpenSSL configured with SSLv3 support: "implicit declaration of function ‘SSLv3_method’" #2181

Description

• Here are some details about my PR
  Implement the envvar workaround as per Python 3.x fails compilation against OpenSSL configured with SSLv3 support: "implicit declaration of function ‘SSLv3_method’" #2181 (comment) for the affected versions.

Tests

• My PR adds the following unit tests (if any)
  N/A