Avoid C89 warning in contrib/minizip/crypt.h.
diff --git a/contrib/minizip/crypt.h b/contrib/minizip/crypt.h
index 9da1537..1cc41f1 100644
--- a/contrib/minizip/crypt.h
+++ b/contrib/minizip/crypt.h
@@ -85,7 +85,7 @@
#define RAND_HEAD_LEN 12
/* "last resort" source for second part of crypt seed pattern */
# ifndef ZCR_SEED2
-# define ZCR_SEED2 3141592654L /* use PI as default pattern */
+# define ZCR_SEED2 3141592654UL /* use PI as default pattern */
# endif
static unsigned crypthead(const char* passwd, /* password string */