This reverts commit fac8d84786.
This fixes fan-out. The track should be created before any tracks or
busses are created that are fed by the MIDI track.
The apparent motivation for fac8d847 was MIDNAM related
(there was code in the GUI that needed the instrument, which was
called from within ::add_routes).
This should no longer be the case, the GUI needs to pick up
instrument changes after track creation via processors changed;
besides MIDI busses were still created before the instrument.
Robin Gareus
dabd5715e9
