Added a missing indirect dependency on PyOpenSSL (via urllib3) to requirements.txt, to work around a broken dependency chain.

 - Legacy-Id: 14636

Author: levkowetz

requirements.txt

@@ -37,6 +37,7 @@ pathlib2>=2.3.0
 Pillow>=3.0
 pyang>=1.7.2,<2.0
 pyflakes>=0.9.2
+pyopenssl>=17.5.0		# Used by urllib3.contrib, which is used by PyQuery but not marked as a dependency
 pyquery>=1.2.13,!=1.2.14	# Pyqyery 1.2.14 fails on some selectors or stacked selectors
 python-dateutil>=2.2
 python-magic>=0.4.6