Disable usage of Expat's config.h.
diff --git a/Modules/expat/xmlparse.c b/Modules/expat/xmlparse.c
index 7c6a801..c46b601 100644
--- a/Modules/expat/xmlparse.c
+++ b/Modules/expat/xmlparse.c
@@ -9,7 +9,9 @@
 #  include "expat.h"
 #  undef XMLPARSEAPI
 #else
+#ifdef HAVE_CONFIG_H
 #include <config.h>
+#endif
 
 #ifdef __declspec
 #  define XMLPARSEAPI(type) __declspec(dllexport) type __cdecl