Marshal time error for amino require time in seconds should be less than 253402300800

[yutianwu]

When we pass a time larger than 253402300800 in time lock request, it will panic:

the root cause is amino require time in seconds less than 253402300800, and a unix timestamp is int64.

const (
	// seconds of 01-01-0001
	minSeconds int64 = -62135596800
	// seconds of 10000-01-01
	maxSeconds int64 = 253402300800

	// nanos have to be in interval: [0, 999999999]
	maxNanos = 999999999
)