Fix commit e473b7c if an inline file happens to have a line break exactly at buffer...

Fix commit e473b7c if an inline file happens to have a line break exactly at buffer limit

The check does only for strlen(line) space and buf_printf will only use at
most space -1 and not print the final character ('\n') in this corner.
Since a missing \n only breaks certificates at the start and end marker,
missing line breaks otherwise do not trigger this error.

Acked-by: Steffan Karger <steffan.karger@fox-it.com>
Message-Id: <1438011191-19389-1-git-send-email-arne@rfc2549.org>
URL: http://article.gmane.org/gmane.network.openvpn.devel/9956

Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit d40cbf0e2601b35bfb1c0551c6f3907b5c5178ff)