Bug 18340: Fix progress bar length

Bug 18340: Fix progress bar length

The progress bar (for background jobs) should be fully filled when 100%
is hit, right? :)
It has been introduced quite long time ago when the size of the progress
bar has been changed from 150 to 200px, and the code has been
refactored.

Test plan:
Launch a big modification/deletion of records/items in a batch.
You should see the progress bar progressing to 100 and reach 100!

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit e424bd0d84d4aa30ceae5e6cea0ee453413f0ef9)
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
(cherry picked from commit 92aff81e1f15fc64af57cc851d703829783555ac)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>