security/py-openssl: Fix RUN_DEPENDS

• Fix RUN_DEPENDS minimum version of cryptography to match that in setup.py [1]
• Remove EXAMPLESDIR, already set and noop'd by USE_PYTHON=concurrent

PR: 222520 [1]
Submitted by: Yasuhiro KIMURA <yasu utahime org> [1]
Approved by: portmgr (blanket)