JSON-RPC: remove 'getblocknumber' deprecated RPC
JSON-RPC: remove 'getblocknumber' deprecated RPC

RPC 'getblockcount' should be used instead.

MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin