Fix wrong byteswap macro being used on mingw32 which was breaking target generation on stratum.
diff --git a/miner.h b/miner.h
index a74740f..3a65d75 100644
--- a/miner.h
+++ b/miner.h
@@ -145,7 +145,7 @@ static inline int fsync (int fd)
# if __BYTE_ORDER == __LITTLE_ENDIAN
# define be32toh(x) bswap_32(x)
# define htobe32(x) bswap_32(x)
-# define htobe64(x) bswap_32(x)
+# define htobe64(x) bswap_64(x)
# elif __BYTE_ORDER == __BIG_ENDIAN
# define be32toh(x) (x)
# define htobe32(x) (x)