Set `discountPerBlock` to 0.002 ETH

We'd like to submit Crypto Corgis to Product Hunt. Before we do that, it could be a good idea to reduce the discountPerBlock parameter on the rescuer contract (https://etherscan.io/address/0x6a86442a9dF14051eA9E2F7230A70fb2B1809f2a#readContract) from 0.001 ETH to 0.002 ETH. The floor price would still remain 0.01 ETH.

In practice, at the current price of 0.3163 ETH per corgi, this would mean a corgi would get 0.02 ETH cheaper per block, until it is ~153 blocks old. After being 153 blocks old, it holds a fixed price of 0.01 ETH.