Allowing for correctly saving the gallery width setting (Bug #1366622)

Currently it checks what width it should be on rendering but really it
should do this on saving.

Change-Id: I7837c3120fa29e2a2dc5c9c63301dfa4543428a4
Signed-off-by: Bob Lyon <bob@katipo.co.nz>
Merge "Allowing for correctly saving the gallery width setting (Bug #1366622)" into 1.9_STABLE