Partially revert cryptography auto-bump for py2

cryptography >= 3.4 doesn't support Py2 anymore, so we have to
constrain it in requirements-pinned.txt and setup.py. Dependabot
keeps bumping the latter regardless, thus the revert.

Signed-off-by: Lukas Puehringer <[email protected]>

Author: Lukas Puehringer

setup.py

@@ -107,7 +107,7 @@
   install_requires = ['six>=1.11.0', 'subprocess32; python_version < "3"'],
   extras_require = {
       'colors': ['colorama>=0.3.9'],
-      'crypto:python_version < "3"': ['cryptography>=3.3.2,<3.5'],
+      'crypto:python_version < "3"': ['cryptography>=3.3.2,<3.4'],
       'crypto:python_version >= "3"': ['cryptography>=3.3.2'],
       'pynacl': ['pynacl>1.2.0']},
   tests_require = 'mock; python_version < "3.3"',