Prevent the default initial sample BGP config from getting loaded

Currently when BGP feature is installed, sample initial config for BGP RIB, peer and network-topologies is installed under ${KARAF_HOME}/etc/opendaylight/bgp directory (files protocols-config.xml and network-topology-config.xml). This sample initial config is read and gets put into the config data store.

http://docs.opendaylight.org/en/stable-carbon/user-guide/bgp-user-guide.html#bgp-protocol-configuration-loader

Having the sample config is definitely helpful as a reference for learning purposes, but having a sample config which gets loaded and live automatically on start is not very desirable for real use scenario. Sample config can be kept as commented so that it is there for reference but will be harmless when loaded.