The old contract was compiled in a such way that `Update` used
all flags except `AllowCall`. Because of this it is impossible to
calculate the key of any record as it requires `Crypto` native contract.
Thus we iterate over all records and transform them into the
serialized representation (`std.Serialize` doesn't work either).
The `Name` field in the resulting structure is empty but this is not a
big deal, `getRecord` continues to work.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>