RNAPRoductAdaptor: move object creation from sth to own function
RNAPRoductAdaptor: move object creation from sth to own function

This will facilitate reusability because this bit of code will be the
same regardless of the SQL query invoked by the sth.

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