Fix for 1364311
https://bugs.launchpad.net/juniperopenstack/r1.1/+bug/1364311
Deleting default loadbalancer plugin in /usr/share/neutron/neutron-dist.conf, otherwise multiple entry would be available
as we added one in /etc/neutron/neutron.conf for opencontrail plugin.

Change-Id: Ie8e44857007b099a95b5675d2cb18bb230f12a4c