Bug 17322 - Translation breaks opac-ics.tt

Bug 17322 - Translation breaks opac-ics.tt

This patch adds newlines to opac-ics.tt that are preserved by the translating process.

To test:
- Apply patch
- Create a translation (perl translate xy-XY)
- With a text editor or poedit, translate misc/translator/po/xy-XY-opac-bootstrap.po
  (it is enough to translate "%s %s %s %s is overdue %sYour copy of........")
- Install language xx-XY and select it for OPAC (perl translate install xy-XY)
- Make sure you have at least a couple of loans, including one overdue
- Go to /cgi-bin/koha/opac-user.pl and click on the link labeled "Download as
  iCal/.ics file"
- Inspect the file in a text editor and/or view the result in a calendar
  appplication. Make sure the data makes sense. Compare it to the english version.

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Katrin Fischer  <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit 756c0f93187174f22d95825f51c4dfa21b11803a)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>