Fix compiler warnings with pyconfig.h

dtool/src/dtoolbase/dtoolbase.h

@@ -94,6 +94,10 @@
 #endif
 #define _WIN32_WINNT 0x0502
 
+#ifdef HAVE_PYTHON
+#include "pyconfig.h"
+#endif
+
 #include "dtoolsymbols.h"
 
 // always include assert.h until drose unbreaks it for opt4