Disable udp2log forward to University of Minnesota

Since the target hostname bento.cs.umn.edu currently does not resolve,
log2udp cannot connect and grep reports tons of

  /bin/grep: writing output: Broken pipe

which fills up udp2log logs on oxygen, which made oxygen ran out of
disk space on 2014-08-16. Hence, we turn off the University of
Minnesota's udp2log stream for now until bento.cs.umn.edu comes online
again.

Bug: 69661
Change-Id: Ic7a8e9c361cb571525c7c911c1b45c076fa4e84e