Upgrade to latest alpine image

Also the image now is an official core image.

Dockerfile

-FROM gliderlabs/alpine:3.1
+FROM alpine:latest
 MAINTAINER Johannes Mitlmeier <dev.jojomi@yahoo.com>
 
 RUN apk add --update \
@@ -11,4 +11,4 @@ RUN adduser www-data -G www-data -H -s /bin/false -D
 EXPOSE 80
 VOLUME /var/www
 
-ENTRYPOINT ["lighttpd", "-D", "-f", "/etc/lighttpd/lighttpd.conf"]
\ No newline at end of file
+ENTRYPOINT ["lighttpd", "-D", "-f", "/etc/lighttpd/lighttpd.conf"]