If user sets USE_COREDNS honour their values even if it breaks things

root/etc/s6-overlay/s6-rc.d/init-wireguard-confs/run

@@ -184,7 +184,7 @@ else
         echo "**** No client conf found. Provide your own client conf as \"/config/wg0.conf\" and restart the container. ****"
         sleep infinity
     fi
-    printf %s "${USE_COREDNS:-false}" > /run/s6/container_environment/USE_COREDNS
+    printf %s "${USE_COREDNS,,:-false}" > /run/s6/container_environment/USE_COREDNS
 fi
 
 # set up CoreDNS

root/etc/s6-overlay/s6-rc.d/svc-coredns/run

@@ -1,7 +1,7 @@
 #!/usr/bin/with-contenv bash
 # shellcheck shell=bash
 
-if netstat -apn | grep -q ":53 "; then
+if netstat -apn | grep -q ":53 " && [[ -z "${USE_COREDNS}" ]]; then
     USE_COREDNS="false"
 fi