Fix MSVC6 warnings. (spotted by Tim Peters)
diff --git a/Modules/cjkcodecs/_cp949.c b/Modules/cjkcodecs/_cp949.c
index f2fa38c..17f51c5 100644
--- a/Modules/cjkcodecs/_cp949.c
+++ b/Modules/cjkcodecs/_cp949.c
@@ -18,7 +18,7 @@
         DBCHAR      code;
 
         if (c < 0x80) {
-            WRITE1(c)
+            WRITE1((unsigned char)c)
             NEXT(1, 1)
             continue;
         }