This fixes another assert(), caused by configuring processors,
before set_processor_state() was called.
Route::configure_processors() will be called later.
---
#3 0x00007ffff2472102 in __GI___assert_fail at assert.c:101
#4 0x00007ffff7a8ca1f in ARDOUR::Route::setup_invisible_processors() at ../libs/ardour/route.cc:5013
#5 0x00007ffff7a7a665 in ARDOUR::Route::configure_processors_unlocked at ../libs/ardour/route.cc:1870
#6 0x00007ffff7a79377 in ARDOUR::Route::configure_processors at ../libs/ardour/route.cc:1719
#7 0x00007ffff7a902c0 in ARDOUR::Route::set_disk_io_point at ../libs/ardour/route.cc:6041
#8 0x00007ffff7a7ea0a in ARDOUR::Route::set_state at ../libs/ardour/route.cc:2679
bc1c3e5c21