Re-enable TLS-1.3 in the OpenSSL backend.

Author: bsergean

ixwebsocket/IXSocketOpenSSL.cpp

@@ -219,11 +219,6 @@ namespace ix
 
             int options = SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3 | SSL_OP_CIPHER_SERVER_PREFERENCE;
 
-#ifdef SSL_OP_NO_TLSv1_3
-            // (partially?) work around hang in openssl 1.1.1b, by disabling TLS V1.3
-            // https://github.com/openssl/openssl/issues/7967
-            options |= SSL_OP_NO_TLSv1_3;
-#endif
             SSL_CTX_set_options(ctx, options);
         }
         return ctx;