message: simplify setAccountDetail statement
diff: @@ -625,14 +625,14 @@ namespace iroha {
  ELSE 1 END AS result)";
  const std::string PostgresCommandExecutor::setAccountDetailBase = R"(
  - PREPARE %s (text, text, text[], text[], text, text) AS
  + PREPARE %s (text, text, text, text) AS
  WITH %s
  inserted AS
  (
  UPDATE account SET data = jsonb_set(
  CASE WHEN data ?$1 THEN data ELSE
  - jsonb_set(data, $3, $6::jsonb) END,
  - $4, $5::jsonb) WHERE account_id=$2 %s
  + jsonb_set(data, array[$1], '{}') END,
  + array[$1, $3], $4::jsonb) WHERE account_id=$2 %s
  RETURNING (1)
  )
  SELECT CASE WHEN EXISTS (SELECT * FROM inserted) THEN 0
  @@ -1100,18 +1100,13 @@ namespace iroha {
  // When creator is not known, it is genesis block
  creator_account_id_ = "genesis";
  }
  - std::string json = "{" + creator_account_id_ + "}";
  - std::string empty_json = "{}";
  - std::string filled_json = "{" + creator_account_id_ + ", " + key + "}";
  std::string val = "\"" + value + "\"";
  - auto cmd = boost::format(
  - "EXECUTE %1% ('%2%', '%3%', '%4%', '%5%', '%6%', '%7%')");
  + auto cmd = boost::format("EXECUTE %1% ('%2%', '%3%', '%4%', '%5%')");
  appendCommandName("setAccountDetail", cmd, do_validation_);
  - cmd = (cmd % creator_account_id_ % account_id % json % filled_json % val
  - % empty_json);
  + cmd = (cmd % creator_account_id_ % account_id % key % val);
  auto str_args = [&account_id, &key, &value] {
  return getQueryArgsStringBuilder()
  