Invalid range of supported datetime values in test

[tsafin]

In the tarantool/tarantool#6725 we are adding validity check for incoming datetime values, and unfortunately it breaks go-tarantool regression test as it was trying to insert invalid (epoch overflow) value in their test:

https://github.com/tarantool/go-tarantool/blob/master/datetime/datetime_test.go#L20

var (
	minTime = time.Unix(0, 0)
	maxTime = time.Unix(1<<63-1, 999999999)
)

maxTime is too big, as we limited with different boundaries (due to c-dt usage).

/**
 * c-dt library uses int as type for dt value, which
 * represents the number of days since Rata Die date.
 * This implies limits to the number of seconds we
 * could safely store in our structures and then safely
 * pass to c-dt functions.
 *
 * So supported ranges will be
 * - for seconds [-185604722870400 .. 185480451417600]
 * - for dates   [-5879610-06-22T00:00Z .. 5879611-07-11T00:00Z]
 */
#define MAX_DT_DAY_VALUE (int64_t)INT_MAX
#define MIN_DT_DAY_VALUE (int64_t)INT_MIN
#define SECS_EPOCH_1970_OFFSET 	((int64_t)DT_EPOCH_1970_OFFSET * SECS_PER_DAY)
#define MAX_EPOCH_SECS_VALUE    \
	(MAX_DT_DAY_VALUE * SECS_PER_DAY - SECS_EPOCH_1970_OFFSET)
#define MIN_EPOCH_SECS_VALUE    \
	(MIN_DT_DAY_VALUE * SECS_PER_DAY - SECS_EPOCH_1970_OFFSET)

Please correct the value used as it's blocking tarantool commit.