Fix pg_dump against 9.1/9.2 servers.

The parallel pg_dump patch forgot to add relpages column to 9.1/9.2 version
of the getTables() query.

Reported by Bernd Helmle.

src/bin/pg_dump/pg_dump.c

@@ -4300,6 +4300,7 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "c.relpersistence, 't'::bool as isscannable, "
+						  "c.relpages, "
 						  "CASE WHEN c.reloftype <> 0 THEN c.reloftype::pg_catalog.regtype ELSE NULL END AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "