Update Dockerfile

Dockerfile

@@ -6,7 +6,7 @@ EXPOSE 1812/udp 1813/udp 3799/udp 80/tcp
 
 RUN echo Acquire::http::Proxy "http://aptcache.infra.flowdat.com/"; > /etc/apt/apt.conf.d/00aptproxy; \
     printf "deb http://archive.debian.org/debian/ jessie main\ndeb-src http://archive.debian.org/debian/ jessie main\ndeb http://security.debian.org jessie/updates main\ndeb-src http://security.debian.org jessie/updates main" > /etc/apt/sources.list; \
-    apt-key adv --recv-keys --keyserver keys.gnupg.net AA8E81B4331F7F50
+    apt-key adv --recv-keys --keyserver keys.gnupg.net AA8E81B4331F7F50 \
     apt-get update && apt-get install -yq freeradius freeradius-mysql freeradius-common vim php5 php5-cli \
     php5-mysql php-pear php-soap php5-xsl cron patch apache2 libapache2-mod-php5 \
     sudo supervisor; \