be64toh and htobe64 needed for Redhat 5.6

--- lib/isccfg/namedconf.c      2019-01-22 13:48:21.013079921 -0500
+++ lib/isccfg/namedconf.c     2019-01-22 13:49:27.472297655 -0500
@@ -20,6 +20,14 @@

#if defined(HAVE_ENDIAN_H)
#include <endian.h>
+#include <byteswap.h>
+# if __BYTE_ORDER == __LITTLE_ENDIAN
+#define be64toh(x) __bswap_64 (x)
+#define htobe64(x) __bswap_64 (x)
+#else
+#define be64toh(x) (x)
+#define htobe64(x) (x)
+#endif
#elif defined(HAVE_SYS_ENDIAN_H)
#include <sys/endian.h>
#elif defined(HAVE_MACHINE_ENDIAN_H)