gmath lib: avoid syntax error with __attribute__ in ctypes wrapping (trunk https://trac.osgeo.org/grass/changeset/71201, trac https://trac.osgeo.org/grass/ticket/3331)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@71203 15284696-431f-4ddb-bdfa-cd5b030d7da7

include/gmath.h

@@ -28,6 +28,12 @@
  /* only include if available */
 #include <grass/la.h>
 #endif
+
+#ifdef CTYPESGEN
+#undef __attribute__
+#define __attribute__(x)
+#endif
+
 #include <stddef.h>
 
 /*solver names */