Bug 22907: Fix new suggestion with strict sql modes

Bug 22907: Fix new suggestion with strict sql modes

With sql_strict_modes turned on, if you try to create a new suggestion
you will get:
Incorrect integer value: '' for column '$INT_COLUMN' at row 1

Test plan:
Turn on strict_sql_modes, create a new suggestion, then edit it.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
JD: Edit after SO, remove unecessary changes (not related to this bug)

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>