Duplicate entries in infrastructureManagers

491a2955 introduced duplicate entries for DBN/DB Netz AG and evb/evb Infrastruktur

Possible solutions for each pair:

1. Delete the old entry, if we are certain that no railML files using that code exist
2. Delete the new, duplicated entry, if it is not already used
3. Add validities on both entries, so one replaces the other