Bug 10185: Fix update 3.09.00.025

Bug 10185: Fix update 3.09.00.025

It can remove all reserves from reserves table when there is no entries
in old_reserves.
This is due to @ai which is set to NULL in
  SET @ai = ( SELECT MAX( reserve_id ) FROM tmp_reserves )
and reserve_id > NULL returns no results in
  INSERT INTO reserves SELECT * FROM tmp_reserves WHERE reserve_id > @ai

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Test plan and comments on second patch.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>