don't check for same seq_region if no seq_region attached to feature
don't check for same seq_region if no seq_region attached to feature

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