rsyslog: security bump to version 7.6.6

Fixes CVE-2014-3634 - potential abort when a message with PRI > 191 was
processed if the "pri-text" property was used in active templates, this
could be abused to a remote denial of service from permitted senders.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Tested-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>