Remove STANDBY_IMAGE_URL support.

This feature only works when /hls streams are viewed over RTMP
and it causes more trouble than it is worth. I would like this
feature but it will require a different implementation.

README.md

@@ -10,15 +10,12 @@ passed to the Docker container as an environment variable.
 You must set the following environment variables:
 
  - `PUBLISH_SECRET`: Secret token for publishing and statistics.
- - `STANDBY_IMAGE_URL`: URL to a PNG image displayed to HLS clients when nothing else is being published.
-    The image is downloaded before starting the server.
 
 This image exposes ports `80` for HTTP and `1935` for RTMP.
 
 ### Example
 
     docker run -e PUBLISH_SECRET=VERY_SECRET_KEY
-               -e STANDBY_IMAGE_URL=http://example.com/standby.png
                -p 80:80 -p 1935:1935 awakening/awakening-nginx-rtmp
 
 

sbin/entrypoint.sh

@@ -2,7 +2,5 @@
 
 set -e
 
-[ ! -z "$STANDBY_IMAGE_URL" ] && curl $STANDBY_IMAGE_URL > /etc/nginx/standby.png
-
 render-templates.sh /etc/nginx/templates/ /etc/nginx/
 exec $@

templates/nginx.conf.tmpl

@@ -109,12 +109,6 @@ rtmp {
             allow publish 127.0.0.1;
             deny publish all;
 
-            # Attempt to show standby image by publishing it
-            # This command must fail if a stream is already publishing
-            exec_pull /usr/local/bin/avconv -loop 1
-                -i /etc/nginx/standby.png -c:v libx264 -tune stillimage -t 10
-                -f flv rtmp://localhost/hls/$name;
-
             hls on;
             hls_path /tmp/hls;
             hls_fragment 15s;