fix: set correct permissions on sudoers files

RHEL validates 0600, while Debian systems expect 0440.

plugins/nginx-vhosts/install

@@ -24,6 +24,7 @@ trigger-nginx-vhosts-install() {
     NGINX_SUDOERS_FILE="/etc/sudoers.d/dokku-openresty"
   fi
 
+  local mode="0440"
   case "$DOKKU_DISTRO" in
     debian | raspbian)
       echo "%dokku ALL=(ALL) NOPASSWD:/usr/sbin/invoke-rc.d $NGINX_INIT_NAME reload, $NGINX_BIN -t, ${NGINX_BIN} -t -c *" >"$NGINX_SUDOERS_FILE"
@@ -48,10 +49,11 @@ trigger-nginx-vhosts-install() {
     centos | fedora | rhel)
       echo "%dokku ALL=(ALL) NOPASSWD:/usr/bin/systemctl reload $NGINX_INIT_NAME, $NGINX_BIN -t, $NGINX_BIN -t -c *" >"$NGINX_SUDOERS_FILE"
       echo "Defaults:dokku !requiretty" >>"$NGINX_SUDOERS_FILE"
+      mode="0600"
       ;;
   esac
 
-  chmod 0440 "$NGINX_SUDOERS_FILE"
+  chmod "$mode" "$NGINX_SUDOERS_FILE"
 
   # if dhparam.pem has not been created, create it the first time
   if [[ ! -f "$NGINX_ROOT/dhparam.pem" ]]; then