Minor

src/hb-uniscribe.cc

diff --git a/src/hb-uniscribe.cc b/src/hb-uniscribe.cc
index 0ca87ec..79e62a0 100644
--- a/src/hb-uniscribe.cc
+++ b/src/hb-uniscribe.cc
@@ -25,6 +25,7 @@
  */
 
 #define _WIN32_WINNT 0x0600
+#define WIN32_LEAN_AND_MEAN
 
 #define HB_SHAPER uniscribe
 #include "hb-shaper-impl-private.hh"