Bug 13669: Re-adds error handling to load_sql

Bug 13669: Re-adds error handling to load_sql

This patch prevents crashing in case an
error is detected when loading a file

To test:
1) Apply patch
2) Mangle kohastructure.sql or any sample
file adding and invalid SQL line
3) Run webinstaller and check that the error
is handled gracefully

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 080f5a6b8ed1c958983bd8f528bda4b32cc76ebf)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>