NFT contract derived from NonFungibleToken macro will panic if receiver account lenght is shorter than sender account.

[VladasZ]

It looks like in case when receiver account is shorter than sender account apply_storage_accounting_hook is trying to refund excess storage to it and fails.

Steps to reproduce:

Edit NFT macro tests like this: VladasZ@8054ed3

It will panic:

called `Result::unwrap()` on an `Err` value: HostError(GuestPanic { panic_msg: "Storage accounting error: Account bob cannot unlock more tokens than it has deposited" })