Bug 25584: Fix minor styling issue

Bug 25584: Fix minor styling issue

This patch makes the button present some space between the icon and the
text.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kelly McElligott <kelly@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 2a0ccf7af26236db9a3e40968cf8f43bc308f142)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
(cherry picked from commit 81fd27153a26154da576eaaba7274968b36f1a3f)

Signed-off-by: Aleisha Amohia <aleishaamohia@hotmail.com>