Update RB config file

In my atlas.config file change

NSAddresses = "lcgrb02.gridpp.rl.ac.uk:7772";
LBAddresses = "lcgrb02.gridpp.rl.ac.uk:9000";

to

NSAddresses = {"lcgrb01.gridpp.rl.ac.uk:7772","lcgrb02.gridpp.rl.ac.uk:7772"};
LBAddresses = {{"lcgrb01.gridpp.rl.ac.uk:9000"},{"lcgrb02.gridpp.rl.ac.uk:9000"}};

to try and use load balancing.