Make tests pass after 2020
and also test that 64 bit integers are properly handled

Without this patch, the failure was
```
unknown location(0): fatal error: in "rpc_tests/rpc_ban": std::runtime_error: JSON value is not an object as expected
test/rpc_tests.cpp(260): last checkpoint
```

I found this when testing reproducible builds for openSUSE Linux packages, building 15 years from now (this is the expected lifespan of today's software)

There is 1 other issue in ./src/qt/test/paymentservertests.cpp that fails to verify a cert that expires in 2022 after 10y.

```
QWARN  : PaymentServerTests::paymentServerTests() PaymentRequestPlus::getMerchant: Payment request: certificate expired or not yet active:  QSslCertificate("3", "01", "Ipbt+DxK8RDQd25/5ueXqw==", (), ("Payment Request Test Merchant"), QMap(), QDateTime(2012-12-10 16:37:24.000 UTC Qt::TimeSpec(UTC)), QDateTime(2022-12-08 16:37:24.000 UTC Qt::TimeSpec(UTC)))
FAIL!  : PaymentServerTests::paymentServerTests() Compared values are not the same
```

faketime '2022-01-01' ninja check-bitcoin-rpc_tests