use nc -q 1 rather than nc -z to wait for mysql

init.sh

@@ -17,7 +17,7 @@ function wait_for_mysql {
 	if [ ! -z "$DATABASE" ] && [ "$DATABASE" == "MYSQL" ]; then
 		PORT=3306
 		if [ ! -z "$DB_PORT" ] ; then PORT="$DB_PORT" ;fi
-		while ! nc -z $DB_HOST $PORT; do sleep 3; done
+		while ! nc -q 1 $DB_HOST $PORT < /dev/null; do sleep 3; done
 	fi
 }