Bug 13872 - Typographical error on columns_settings.tt

Bug 13872 - Typographical error on columns_settings.tt

Test plan:
1) Go to url 'koha-tmpl/intranet-tmpl/prog/en/modules/help/admin/columns_settings.tt' line 9 and check the typo "columsn" and change for columns.
2) See also changes for Column settings to Columns settings at lines 3 and 15
3) Apply the patch
4) Repeat step 1 and chek if the typo is fixed or go to Administration > Additional parameters > Configure columns and go to Help page.

Sponsored-by: Universidad de El Salvador
Signed-off-by: Hector Eduardo Castro Avalos <hector.hecaxmmx@gmail.com>
Typo is fixed
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>