Make comparison in warning printout more robust

In the check for duplicate algorithms in the configuration of DataOnDemand, the Calo RawBank decoding algorithms are returned as objects, not strings. This was causing the check to always fail, which resulted in always printing out the entire configuration of the algorithm.

Cherry-picked from !3015 (merged) on run2-patches. I don't know if the DoD is still relevant in master, but as long as this file is there it probably makes sense to fix it...