Compilation failure when linking C extension to OpenSSL with DES support disabled

[chrisnovakovic]

When linking to a copy of OpenSSL that is built without DES support (./Configure no-des):

src/constants.c, line 494, column 5: error: use of undeclared identifier 'xmlSecOpenSSLTransformDes3CbcId'
    PYXMLSEC_ADD_TRANSFORM_CONSTANT(TransformDes3Cbc, "DES3");
    ^
src/constants.c, line 464, column 33: note: expanded from macro 'PYXMLSEC_ADD_TRANSFORM_CONSTANT'
    tmp = PyXmlSec_TransformNew(xmlSec ## name ## Id); \
                                ^
<scratch space>:31:1: note: expanded from here
xmlSecTransformDes3CbcId
^
include/xmlsec/openssl/symbols.h, line 67, column 49: note: expanded from macro 'xmlSecTransformDes3CbcId'
#define xmlSecTransformDes3CbcId                xmlSecOpenSSLTransformDes3CbcId
                                                ^
src/constants.c, line 495, column 5: error: use of undeclared identifier 'xmlSecOpenSSLTransformKWDes3Id'
    PYXMLSEC_ADD_TRANSFORM_CONSTANT(TransformKWDes3, "KW_DES3");
    ^
src/constants.c, line 464, column 33: note: expanded from macro 'PYXMLSEC_ADD_TRANSFORM_CONSTANT'
    tmp = PyXmlSec_TransformNew(xmlSec ## name ## Id); \
                                ^
<scratch space>:34:1: note: expanded from here
xmlSecTransformKWDes3Id
^
include/xmlsec/openssl/symbols.h, line 68, column 49: note: expanded from macro 'xmlSecTransformKWDes3Id'
#define xmlSecTransformKWDes3Id                 xmlSecOpenSSLTransformKWDes3Id
                                                ^

Support for DES, 3DES and KW-3DES should be conditional on the value of XMLSEC_NO_DES if TLS support is being provided by OpenSSL.