BUG/MINOR: http-ana: Don't eval front after-response rules if stopped on back

http-after-response rules evaluation must be stopped after a "allow". It
means the frontend ruleset must not be evaluated if a "allow" was performed
in the backend ruleset. Internally, the evaluation must be stopped if on
HTTP_RULE_RES_STOP return value. Only the "allow" action is concerned by
this change.

Thanks to this patch, http-response and http-after-response behave in the
same way.

This patch should be backported as far as 2.2.

(cherry picked from commit 597909f4e67866c4f3ecf77f95f2cd4556c0c638)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/http_ana.c b/src/http_ana.c
index 4c765cb..980731d 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -3004,7 +3004,7 @@
 	}
 
 	ret = http_res_get_intercept_rule(s->be, &s->be->http_after_res_rules, s);
-	if ((ret == HTTP_RULE_RES_CONT || ret == HTTP_RULE_RES_STOP) && sess->fe != s->be)
+	if (ret == HTTP_RULE_RES_CONT && sess->fe != s->be)
 		ret = http_res_get_intercept_rule(sess->fe, &sess->fe->http_after_res_rules, s);
 
   end: