Remove broken newline

[eriktim]

When setting AUTO_CREATE_TOPICS=false and inspecting the server.properties in the Docker container I noticed the "\n" gets printed in the file as is. >> will automatically add a newline for us so I removed the prefix.

You can try by running:

$ echo "foo" > test.txt
$ echo "bar" >> test.txt
$ cat test.txt
foo
bar

[eriktim]

Did not notice this before but fixes #9.

[obalunenko]

Hi @eriktim
This repository is not maintained.
You can use this one: https://github.com/obalunenko/docker-kafka-zookeeper .
It already has pre-build images for all Kafka with zookeeper versions published on the official site https://kafka.apache.org/downloads