disable gelf due to problems with hive

https://bugzilla.wikimedia.org/show_bug.cgi?id=70203
stat1002:~$ hive
Unable to determine Hadoop version information.
'hadoop version' returned:
No default-logstash-fields.properties resource present, using defaults Hadoop 2.3.0-cdh5.0.2

Change-Id: Ice64f900a8948110c36a9007208953a1dfe5b856