fixed a bug in BinMapper: division by zero (#452)

* fixed a bug in BinMapper: division by zero

* Revert "fixed a bug in BinMapper: division by zero"

This reverts commit 228380284f6a9ba174982e210e14d0aecde8e837.

* added CHECK for min_data_in_bin and fixed typo

src/io/config.cpp

@@ -221,7 +221,8 @@ void IOConfig::Set(const std::unordered_map<std::string, std::string>& params) {
   GetString(params, "ignore_column", &ignore_column);
   GetString(params, "categorical_column", &categorical_column);
   GetInt(params, "min_data_in_leaf", &min_data_in_leaf);
-  GetInt(params, "min_dato_in_bin", &min_data_in_bin);
+  GetInt(params, "min_data_in_bin", &min_data_in_bin);
+  CHECK(min_data_in_bin > 0);
   GetDouble(params, "max_conflict_rate", &max_conflict_rate);
   GetBool(params, "enable_bundle", &enable_bundle);
   GetBool(params, "adjacent_bundle", &adjacent_bundle);