[PLUG] Apache update broke Nagios check on Debian8

[JP Vossen <jp@jpsdomain.org>]

On Saturday I updated a Debian 8 system:
[UPGRADE] apache2:amd64 2.4.10-10+deb8u7 -> 2.4.10-10+deb8u8
[UPGRADE] apache2-bin:amd64 2.4.10-10+deb8u7 -> 2.4.10-10+deb8u8
[UPGRADE] apache2-data:amd64 2.4.10-10+deb8u7 -> 2.4.10-10+deb8u8
[UPGRADE] apache2-mpm-prefork:amd64 2.4.10-10+deb8u7 -> 2.4.10-10+deb8u8
[UPGRADE] apache2-utils:amd64 2.4.10-10+deb8u7 -> 2.4.10-10+deb8u8

And that broke a trivial Nagios (nagios3-3.5.1.dfsg-2+b1) check:
----
define service{
    use                    local-service
    host_name              drake
    service_description    HTTP
    check_command          check_http!-u '/intranet/'
}
----

Both live on the same server VM, Nagios was not updated, and I've 
manually restarted:
	apache2
	nagios-nrpe-server
	nagios3

It WORKS when I run it manually by IP or hostname:
----
# /usr/lib/nagios/plugins/check_http -H 127.0.0.1 -u '/intranet/'
HTTP OK: HTTP/1.1 200 OK - 9985 bytes in 0.002 second response time 
|time=0.001531s;;;0.000000 size=9985B;;;0
----

And it works just fine from `curl`, but it FAILS when Nagios runs it 
with an error email:
----
Subject: ** PROBLEM Service Alert: drake/HTTP is WARNING **

***** Nagios *****

Notification Type: PROBLEM

Service: HTTP
Host: drake
Address: 127.0.0.1
State: WARNING

Date/Time: Mon Mar 6 19:58:15 EST 2017

Additional Info:

HTTP WARNING: HTTP/1.1 400 Bad Request - 493 bytes in 0.001 second 
response time
----

And the Apache log is different, but not useful to me, the first line is 
a failed Nagios run, the second is the manual run from above:
----
127.0.0.1 - - [06/Mar/2017:20:08:11 -0500] "GET /intranet/ HTTP/1.1" 400 
0 "-" "-"
127.0.0.1 - - [06/Mar/2017:20:08:40 -0500] "GET /intranet/ HTTP/1.1" 200 
9985 "-" "check_http/v2.1.1 (monitoring-plugins 2.1.1)"
----

This Nagios check has Just Worked for years, and it broke 2017-03-04 
01:54 PM, *right* AFTER I ran the update.

Clues?  Thanks in advance...
JP
--  -------------------------------------------------------------------
JP Vossen, CISSP | http://www.jpsdomain.org/ | http://bashcookbook.com/
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