Fixed NPE in group lookup if attribute is not present
Fixed NPE in group lookup if attribute is not present

xdarklight/mamute,JamesSullivan/mamute,cristianospsp/mamute,superm1a3/mamute,JamesSullivan/mamute,GEBIT/mamute,cristianospsp/mamute,GEBIT/mamute,dhieugo/mamute,xdarklight/mamute,MatejBalantic/mamute,c2tarun/mamute,bradparks/mamute,caelum/mamute,csokol/mamute,khajavi/mamute,shomabegoo/shomabegoo,JamesSullivan/mamute,jasonwjones/mamute,shomabegoo/shomabegoo,csokol/mamute,csokol/mamute,superm1a3/mamute,dhieugo/mamute,xdarklight/mamute,caelum/mamute,GEBIT/mamute,jasonwjones/mamute,c2tarun/mamute,bradparks/mamute,jasonwjones/mamute,bradparks/mamute,caelum/mamute,MatejBalantic/mamute,khajavi/mamute,c2tarun/mamute,superm1a3/mamute,khajavi/mamute,shomabegoo/shomabegoo,cristianospsp/mamute,MatejBalantic/mamute,shomabegoo/shomabegoo,dhieugo/mamute