Avoid 0788 duplication from 2.3 failure

Recent installs of 2.3, or upgrades during 2.3, will have introduced
0788 already into the upgrade process -- meaning that the 2.3-2.4.0
script will rollback the entire transaction if it hits the duplicated
0788. Instead, move 0788 into its own transaction to increase the
chances that the 2.3-2.4.0 script will work for sites that stay up to
date or that recently installed Evergreen.

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Mike Rylander <mrylander@gmail.com>