frontend: Fix incorrect text wrap

In Japanese, caption for remaping control-alt-del is broken into two
lines.

Change-Id: I0c62c286d2c85d43da5aec89df01f3d43e63171d
Bug-Url: https://bugzilla.redhat.com/1080322
Signed-off-by: Frantisek Kobzik <fkobzik@redhat.com>