Added info_type is null condition to xref sql
Added info_type is null condition to xref sql

willmclaren/ensembl,james-monkeyshines/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl,at7/ensembl,james-monkeyshines/ensembl,at7/ensembl,danstaines/ensembl,mjg17/ensembl,Ensembl/ensembl,at7/ensembl,mjg17/ensembl,muffato/ensembl,willmclaren/ensembl,Ensembl/ensembl,muffato/ensembl,danstaines/ensembl,james-monkeyshines/ensembl,mjg17/ensembl,danstaines/ensembl,at7/ensembl,Ensembl/ensembl,muffato/ensembl,muffato/ensembl,mjg17/ensembl