remove ipv6 conf from nginx proxy if ipv6 not enabled

hosting/proxy/10-listen-on-ipv6-by-default.sh

@@ -8,7 +8,7 @@ NGINX_CONF_FILE="/etc/nginx/nginx.conf"
 DEFAULT_CONF_FILE="/etc/nginx/conf.d/default.conf"
 
 # check if we have ipv6 available
-if [ ! -f "/proc/net/if_jonnyinet6" ]; then
+if [ ! -f "/proc/net/if_inet6" ]; then
     # ipv6 not available so delete lines from nginx conf
     if [ -f "$NGINX_CONF_FILE" ]; then
         sed -i '/listen  \[::\]/d' $NGINX_CONF_FILE