xmlsecurity: fix DrMemory warning

Presumably that was the intent?

Change-Id: Ibfca90041d6913827d2f329bab448afe4d725b46

xmlsecurity/source/xmlsec/saxhelper.cxx

@@ -135,7 +135,7 @@ SAXHelper::SAXHelper( )
     {
         xmlSAXVersion(m_pParserCtxt->sax, 1);
 
-        if( m_pParserCtxt->inputTab[0] != nullptr )
+        if (m_pParserCtxt->inputTab != nullptr)
         {
             m_pParserCtxt->inputTab[0] = nullptr ;
         }