Bug 18819: "UNIMARC is used in Europe" text changed to "UNIMARC is used in a few...

Bug 18819: "UNIMARC is used in Europe" text changed to "UNIMARC is used in a few European countries"

To test
1/ run installer and notice the inaccurate text "UNIMARC is used in Europe"
2/ run the patch attached
3/ run the installer and notice that the updated text "UNIMARC is used in a few European countries"is now present

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>