Bug 18778 - Translatability: Get rid of tt directive in translation for item-status.inc

Bug 18778 - Translatability: Get rid of tt directive in translation for item-status.inc

The file opac-tmpl/bootstrap/en/includes/item-status.inc exposes a template directive where translators should not be confronted with.

"%s %s [%%#- This include takes two parameters: an item structure and an "
"optional loan (issue) structure. The issue structure is used by course "
"reserves pages, which do not use an API to fetch items that populates item."
"datedue. -%%] %s %s %s %s "

This patch fixes new lines inside a tt directive (comment).
It is merely a string patch.

To test:
Verify that the code changes make sense.
(Bonus test: create a new language 'aa-AA', verify that line above does not
show up in aa-AA-opac-bootstrap.po)

NOTE: Followed test plan similar to bug 18776 comment 3.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>