create_release_tasks.pl: explicitly dereference arguments to 'keys'
create_release_tasks.pl: explicitly dereference arguments to 'keys'

Being able to pass a scalar to e.g. keys was an experimental feature
that was added in Perl 5.14 and since declared failed, thus causing the
script to fail with an "Experimental keys on scalar is now forbidden"
error.

muffato/ensembl,muffato/ensembl,muffato/ensembl,muffato/ensembl,james-monkeyshines/ensembl,james-monkeyshines/ensembl,Ensembl/ensembl,Ensembl/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl,Ensembl/ensembl,james-monkeyshines/ensembl