BUG/MINOR: http-ana: increment internal_errors counter on response error

BUG/MINOR: http-ana: increment internal_errors counter on response error

A bug was introduced in the commit cff0f739e51 ("MINOR: counters: Review
conditions to increment counters from analysers"). The internal_errors
counter for the target server was incremented twice. The counter for the
session listener needs to be incremented instead.

This must be backported everywhere the commit cff0f739e51 is.

(cherry picked from commit 9a006f9641ceb353c007f8f7e8ae949ace786099)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 84426cd01cd805dc26570312d6c8485f67939b37)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>