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

RPC 'getblockcount' should be used instead.

IngCr3at1on/paycoin,thommyV91/Suck-a-Coin,LambocoinFoundation/Lambocoin,thommyV91/Suck-a-Coin,IngCr3at1on/paycoin,mitchellcash/paycoin,mitchellcash/paycoin,ligerzero459/paycoin,PaycoinFoundation/paycoin,ligerzero459/paycoin,ligerzero459/paycoin,PaycoinFoundation/paycoin,PaycoinFoundation/paycoin,IngCr3at1on/paycoin,LambocoinFoundation/Lambocoin,thommyV91/Suck-a-Coin,mitchellcash/paycoin,mitchellcash/paycoin,thommyV91/Suck-a-Coin,IngCr3at1on/paycoin,LambocoinFoundation/Lambocoin,ligerzero459/paycoin,PaycoinFoundation/paycoin,LambocoinFoundation/Lambocoin