Fix the 'reconfigure_mapping_untunable' test
Fix the 'reconfigure_mapping_untunable' test

The value from the config is ignored since it is mapped, so it must be
set using the mapping.

mathstuf/sprokit,Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,Kitware/sprokit,linus-sherrill/sprokit,Kitware/sprokit,linus-sherrill/sprokit,Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,mathstuf/sprokit