Escape '+' in 'uname -v' output in freebsd_check_running_version()

The output from 'uname -v' is later used in a regular expression, so the '+'
from a time zone would be interpreted there, and must therefore be escaped.
Merge pull request #51 from mstock/bugfix/running-kernel-on-kfreebsd

Escape '+' in 'uname -v' output in freebsd_check_running_version()
check_raid: Updating to 3.2.0
check_httpd_status: Updating to rev153
check_mongodb: Updating to 60b639ef4c
check_zone_rrsig_expiration: Updateing to 1.11
percona-nagios-plugins: Updating to 1.1.4
Merge branch 'check_httpd_status_153' into update
Merge branch 'check_mongodb_60b639ef4c' into update
Merge branch 'check_raid_32' into update
Merge branch 'check_zone_rrsig_expiration_111' into update
Merge branch 'percona-nagios-plugins_114' into update