ctype.c only wants git-compat-util.h

The implementation of sane ctype macros only depends on symbols in
git-compat-util.h not cache.h

Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

ctype.c

@@ -3,7 +3,7 @@
  *
  * No surprises, and works with signed and unsigned chars.
  */
-#include "cache.h"
+#include "git-compat-util.h"
 
 enum {
 	S = GIT_SPACE,