message: rpc: make estimatesmartfee argument naming consistent with documentation
  Github-Pull:
  Rebased-From:
diff: @@ -115,7 +115,7 @@ static const CRPCConvertParam vRPCConvertParams[] =
  { "keypoolrefill", 0, "newsize" },
  { "getrawmempool", 0, "verbose" },
  { "estimatefee", 0, "nblocks" },
  - { "estimatesmartfee", 0, "nblocks" },
  + { "estimatesmartfee", 0, "conf_target" },
  { "estimaterawfee", 0, "conf_target" },
  { "estimaterawfee", 1, "threshold" },
  { "prioritisetransaction", 1, "dummy" },
  