Removes m.data from SELECT statement

Removes the m.data field from the SQL query within get_metadata_records_for_harvester as it is retrieved separately by get_metadata_payload.
Removes LIMIT from SQL statement

There was a LIMIT of 5 records being returned to counteract the bug during testing which is not needed now.
Merge pull request #41 from oceanzus/m057_tune_sql

Removes m.data from SELECT statement