Fix MSVC6 warnings. (spotted by Tim Peters)
diff --git a/Modules/cjkcodecs/_hz.c b/Modules/cjkcodecs/_hz.c
index 50805b1..19f910c 100644
--- a/Modules/cjkcodecs/_hz.c
+++ b/Modules/cjkcodecs/_hz.c
@@ -36,10 +36,10 @@
 
         if (c < 0x80) {
             if (state->i == 0) {
-                WRITE1(c)
+                WRITE1((unsigned char)c)
                 NEXT(1, 1)
             } else {
-                WRITE3('~', '}', c)
+                WRITE3('~', '}', (unsigned char)c)
                 NEXT(1, 3)
                 state->i = 0;
             }