rust: respect AUTO_UPDATE (#42)

games/rust/entrypoint.sh

@@ -4,8 +4,13 @@ cd /home/container
 # Make internal Docker IP address available to processes.
 export INTERNAL_IP=`ip route get 1 | awk '{print $(NF-2);exit}'`
 
-# Update Rust Server
-./steamcmd/steamcmd.sh +force_install_dir /home/container +login anonymous +app_update 258550 +quit
+
+## if auto_update is not set or to 1 update
+if [ -z ${AUTO_UPDATE} ] || [ "${AUTO_UPDATE}" == "1" ]; then
+	./steamcmd/steamcmd.sh +force_install_dir /home/container +login anonymous +app_update 258550 +quit
+else
+    echo -e "Not updating game server as auto update was set to 0. Starting Server"
+fi
 
 # Replace Startup Variables
 MODIFIED_STARTUP=`eval echo $(echo ${STARTUP} | sed -e 's/{{/${/g' -e 's/}}/}/g')`