Support cryptography 35.0.0 for all modules except openssl_pkcs12 (#294)

* Add some workarounds for cryptography 35.0.0.

* Make fix work with very old cryptography versions as well (which supported multiple backends).

* [TEMP] Disable openssl_pkcs12 tests to see whether everything else works.

* Revert "[TEMP] Disable openssl_pkcs12 tests to see whether everything else works."

This reverts commit 3f905bc795.

* Add changelog fragment.

* Remove unnecessary assignment.

* Simplify code change.

* [TEMP] Disable openssl_pkcs12 tests to see whether everything else works.

* Revert "[TEMP] Disable openssl_pkcs12 tests to see whether everything else works."

This reverts commit fdb210528e.

plugins/module_utils/crypto/_obj2txt.py

@@ -20,6 +20,10 @@ from __future__ import absolute_import, division, print_function
 __metaclass__ = type
 
 
+# WARNING: this function no longer works with cryptography 35.0.0 and newer!
+#          It must **ONLY** be used in compatibility code for older
+#          cryptography versions!
+
 def obj2txt(openssl_lib, openssl_ffi, obj):
     # Set to 80 on the recommendation of
     # https://www.openssl.org/docs/crypto/OBJ_nid2ln.html#return_values