Specify crontab - instead of crontab -u root

This change was missing from a previous setup.sh change.

Change-Id: Id67c8d78ea421a04d77c0b2dab1330441042530c

setup.sh

diff --git a/setup.sh b/setup.sh
index 5975ff0..3b8a81a 100755
--- a/setup.sh
+++ b/setup.sh
@@ -39,7 +39,7 @@
 # Install the needed packages and setup the environment
 apt-get install -y gcc openjdk-7-jdk ant maven zip
 rm -rf $path
-echo "0 0 * * * /usr/pb/setup.sh build >> /var/log/pb.log" | crontab -u root
+echo "0 0 * * * /usr/pb/setup.sh build >> /var/log/pb.log" | crontab -
 adduser --uid 1337 --disabled-password --gecos ,,, worker