avoid a perl warning when comparing Analysis objects that have undefined attributes
avoid a perl warning when comparing Analysis objects that have undefined attributes

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