Fix broken calc_MoM command

[who-biz]

Prior to fix:

./chips-cli -testnet calc_MoM 100 1
error code: -1
error message:
calc_MoM


Result:
n    (numeric) The current block count

Examples:
> bitcoin-cli getblockcount 
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id": "curltest", "method": "getblockcount", "params": []}' -H 'content-type: text/plain;' http://127.0.0.1:8332/

After fix:

./chips-cli -testnet calc_MoM 100 1
{
  "coin": "CHIPS",
  "height": 100,
  "MoMdepth": 1,
  "MoM": "64466cf635c71f921cd34a7afe5d9e979cb5c21a7a19985954e9aa04abf7467c"
}