fix for tandems now alleles coming from different source table
fix for tandems now alleles coming from different source table

willmclaren/ensembl-variation,dbolser/ensembl-variation,dbolser/ensembl-variation,dbolser-ebi/ensembl-variation,willmclaren/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,dbolser-ebi/ensembl-variation,willmclaren/ensembl-variation,dbolser-ebi/ensembl-variation,Ensembl/ensembl-variation,Ensembl/ensembl-variation,willmclaren/ensembl-variation,dbolser/ensembl-variation,Ensembl/ensembl-variation