Pull from alpine linux CDN to fix build errors on quay.

Author: pieterlange

Dockerfile

@@ -3,8 +3,8 @@ FROM alpine:3.5
 
 MAINTAINER Pieter Lange <pieter@ptlc.nl>
 
-RUN echo "http://dl-4.alpinelinux.org/alpine/edge/community/" >> /etc/apk/repositories && \
-    echo "http://dl-4.alpinelinux.org/alpine/edge/testing/" >> /etc/apk/repositories && \
+RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/community/" >> /etc/apk/repositories && \
+    echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing/" >> /etc/apk/repositories && \
     apk add --update openvpn bash easy-rsa libintl inotify-tools openvpn-auth-pam google-authenticator pamtester && \
     apk add --virtual temppkg gettext &&  \
     cp /usr/bin/envsubst /usr/local/bin/envsubst && \