[release-1.8] Disable Modsecurity from internal processing which affects large ingresses (#10375)

* Disable Modsecurity from interanl processing

* Fix modsecurity check logic

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Co-authored-by: mley <[email protected]>

Author: k8s-infra-cherrypick-robot

rootfs/etc/nginx/template/nginx.tmpl

@@ -710,6 +710,11 @@ http {
 
     # default server, used for NGINX healthcheck and access to nginx stats
     server {
+        # Ensure that modsecurity will not run on an internal location as this is not accessible from outside
+        {{ if $all.Cfg.EnableModsecurity }}
+        modsecurity off;
+        {{ end }}
+
         listen 127.0.0.1:{{ .StatusPort }};
         set $proxy_upstream_name "internal";