Fix hdfs data path 'external' to 'raw'

The path for raw data in hdfs has been changed from

  /wmf/data/external

to

  /wmf/data/raw

on 2014-07-16. Hence, we reflect this change in refinery too.

Change-Id: Ie9ecdc5380fba78fbc6e045f132c4d9441e2d4e0