[ENSCORESW-596]. Added disconnects post querying for ID lookups.
[ENSCORESW-596]. Added disconnects post querying for ID lookups.

Nick in Ensembl Genomes has seen an issue with bacteria databases where
we exceed the number of connections on MySQL. As we loop through DBAdaptors
we do not disconnect. That means an ID which appears later on will have
opened all prior databases. The connection is still active. We now
disconnect this.

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