Added configmap option to disable IPv6 in nginx DNS resolver (#1992)

docs/user-guide/configmap.md

@@ -37,11 +37,12 @@ The following table shows a configuration option's name, type, and the default v
 |[client‑header‑timeout](#client-header-timeout)|int|60|
 |[client‑body‑buffer‑size](#client-body-buffer-size)|string|"8k"|
 |[client‑body‑timeout](#client-body-timeout)|int|60|
-|[disable‑access‑log](#disable-access-log)|bool|"false"|
-|[disable‑ipv6](#disable-ipv6)|bool|"false"|
-|[enable‑underscores‑in‑headers](#enable-underscores-in-headers)|bool|"false"|
-|[ignore‑invalid‑headers](#ignore-invalid-headers)|bool|"true"|
-|[enable‑vts‑status](#enable-vts-status)|bool|"false"|
+|[disable‑access‑log](#disable-access-log)|bool|false|
+|[disable‑ipv6](#disable-ipv6)|bool|false|
+|[disable‑ipv6‑dns](#disable-ipv6-dns)|bool|false|
+|[enable‑underscores‑in‑headers](#enable-underscores-in-headers)|bool|false|
+|[ignore‑invalid‑headers](#ignore-invalid-headers)|bool|true|
+|[enable‑vts‑status](#enable-vts-status)|bool|false|
 |[vts‑status‑zone‑size](#vts-status-zone-size)|string|"10m"|
 |[vts‑default‑filter‑key](#vts-default-filter-key)|string|"$geoip_country_code country::*"|
 |[retry‑non‑idempotent](#retry-non-idempotent)|bool|"false"|
@@ -211,6 +212,10 @@ _References:_
 
 Disable listening on IPV6. By default this is disabled.
 
+## disable-ipv6-dns
+
+Disable IPV6 for nginx DNS reslover. By default this is disabled.
+
 ## enable-underscores-in-headers
 
 Enables underscores in header names. By default this is disabled.
@@ -707,4 +712,4 @@ Enables or disables [buffering of responses from the proxied server](http://ngin
 
 ## limit-request-status-code
 
-Sets the [status code to return in response to rejected requests](http://nginx.org/en/docs/http/ngx_http_limit_req_module.html#limit_req_status).Default: 503
+Sets the [status code to return in response to rejected requests](http://nginx.org/en/docs/http/ngx_http_limit_req_module.html#limit_req_status).Default: 503