rpc: fix -rpcclienttimeout 0 option
rpc: fix -rpcclienttimeout 0 option

Former-commit-id: b62ddf7f662abadaf1580ed126c52512d6400b8e
syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin