Removed redundant code in SSL.py that depended on old version of cryptography (#1290)

Author: julianz-

src/OpenSSL/SSL.py

@@ -163,20 +163,11 @@
 DTLS_SERVER_METHOD = 11
 DTLS_CLIENT_METHOD = 12
 
-try:
-    SSL3_VERSION = _lib.SSL3_VERSION
-    TLS1_VERSION = _lib.TLS1_VERSION
-    TLS1_1_VERSION = _lib.TLS1_1_VERSION
-    TLS1_2_VERSION = _lib.TLS1_2_VERSION
-    TLS1_3_VERSION = _lib.TLS1_3_VERSION
-except AttributeError:
-    # Hardcode constants for cryptography < 3.4, see
-    # https://github.com/pyca/pyopenssl/pull/985#issuecomment-775186682
-    SSL3_VERSION = 768
-    TLS1_VERSION = 769
-    TLS1_1_VERSION = 770
-    TLS1_2_VERSION = 771
-    TLS1_3_VERSION = 772
+SSL3_VERSION = _lib.SSL3_VERSION
+TLS1_VERSION = _lib.TLS1_VERSION
+TLS1_1_VERSION = _lib.TLS1_1_VERSION
+TLS1_2_VERSION = _lib.TLS1_2_VERSION
+TLS1_3_VERSION = _lib.TLS1_3_VERSION
 
 OP_NO_SSLv2 = _lib.SSL_OP_NO_SSLv2
 OP_NO_SSLv3 = _lib.SSL_OP_NO_SSLv3