fixed a typo.

skyred · skyred · commit 5bfd6d661ad0 · 2015-08-23T20:35:36.000+08:00
diff --git a/Dockerfile b/Dockerfile
@@ -2,7 +2,7 @@ FROM debian:jessie
 
 MAINTAINER NGINX Docker Maintainers "docker-maint@nginx.com"
 
-RUN echo "http://httpredir.debian.org/debian/ sid/main" >> /etc/apt/sources.list
+RUN echo "deb http://httpredir.debian.org/debian sid main" >> /etc/apt/sources.list
 
 ENV NGINX_VERSION 1.9.3-1~jessie
 
