Embulk freezes when I specify where condition

Hi team,

I am using `embulk-input-oracle` for fetching data. This works fine when I write query without any `WHERE` clause. But when I specify a WHERE clause it just freezes.

This is the config we are using:

```yml
in:
type: oracle
driver_path: ojdbc7-12.1.0.2.jar
url: jdbc:oracle:thin:@something.com:1526/DB
user: ABC
password: "PASSWORD"
query: "SELECT * FROM SCHEMA.TABLE WHERE ABC_DATE > to_date('01 JAN 2019','DD MON YY')"
fetch_rows: 20000
connect_timeout: 100
```

Is there any flag to be set for this to work?