added check for running docker daemon

added code to check if docker daemon is running since it is needed to run database initialization.

prepare.sh

@@ -1,5 +1,11 @@
 #!/bin/sh
 #
+# check if docker is running
+if ! (docker ps >/dev/null 2>&1)
+then
+	echo "docker daemon not running, will exit here!"
+	exit
+fi
 echo "Preparing folder init and creating ./init/initdb.sql"
 mkdir ./init >/dev/null 2>&1
 mkdir -p ./nginx/ssl >/dev/null 2>&1