[hb-old] Fix warnings

src/hb-old/harfbuzz-shaper.cpp

diff --git a/src/hb-old/harfbuzz-shaper.cpp b/src/hb-old/harfbuzz-shaper.cpp
index f410780..d1e2335 100644
--- a/src/hb-old/harfbuzz-shaper.cpp
+++ b/src/hb-old/harfbuzz-shaper.cpp
@@ -465,8 +465,10 @@
 #define DEBUG if (1) ; else printf
 #endif
 
+#if 0
 #define DefaultLangSys 0xffff
 #define DefaultScript HB_MAKE_TAG('D', 'F', 'L', 'T')
+#endif
 
 enum {
     RequiresGsub = 1,