dockerfile: Reduce ENV lines to single layer

* Results in a slightly simpler docker image.

Author: kylemanna

Dockerfile

@@ -12,13 +12,11 @@ RUN echo "http://dl-cdn.alpinelinux.org/alpine/edge/testing/" >> /etc/apk/reposi
     rm -rf /tmp/* /var/tmp/* /var/cache/apk/* /var/cache/distfiles/*
 
 # Needed by scripts
-ENV OPENVPN /etc/openvpn
-ENV EASYRSA /usr/share/easy-rsa
-ENV EASYRSA_PKI $OPENVPN/pki
-ENV EASYRSA_VARS_FILE $OPENVPN/vars
-
-# Prevents refused client connection because of an expired CRL
-ENV EASYRSA_CRL_DAYS 3650
+ENV OPENVPN=/etc/openvpn
+ENV EASYRSA=/usr/share/easy-rsa \
+    EASYRSA_CRL_DAYS=3650 \
+    EASYRSA_PKI=$OPENVPN/etc/pki \
+    EASYRSA_VARS_FILE=$OPENVPN/vars
 
 VOLUME ["/etc/openvpn"]