Remove unused variable and access to legacy metadata.
Remove unused variable and access to legacy metadata.

The latter breaks analysing of old output files (which probably don't
exist with free energy data...) which will neatly be fixed by merging
into master, which uses identical data structures for legacy and new
metadata. So breakage is very temporary...

hande-qmc/hande,hande-qmc/hande,hande-qmc/hande,ruthfranklin/hande,hande-qmc/hande,hande-qmc/hande