Fixed bug, where using random background only would give an error for xenTtro2
Fixed bug, where using random background only would give an error for xenTtro2

simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs,simonvh/gimmemotifs