Change fillfactor of tables oorder and order_line to 50%.

There is a big problem with these two tables. They receive
INSERTs, then every inserted row is UPDATEd in a batch
operation some time later. If the fillfactor is larger than
50% the benchmark is not long-term stable, because the
number of active pages in the two tables will increase.
This behavior guarantees that at some point the active
data set no longer fits into shared buffers, at which
point the performance goes down dramatically.

run/sql.postgres/extraCommandsBeforeLoad.sql

@@ -1,5 +1,5 @@
-ALTER TABLE bmsql_oorder SET (FILLFACTOR = 80);
-ALTER TABLE bmsql_order_line SET (FILLFACTOR = 80);
+ALTER TABLE bmsql_oorder SET (FILLFACTOR = 50);
+ALTER TABLE bmsql_order_line SET (FILLFACTOR = 50);
 ALTER TABLE bmsql_warehouse SET (FILLFACTOR = 50);
 ALTER TABLE bmsql_district SET (FILLFACTOR = 79);
 ALTER TABLE bmsql_customer SET (FILLFACTOR = 90);