Fix T65558: Crash on adding linked scene to Video Sequence Editor

This commit fixes crash but the possible 3D sound is still missing.
Also, sound from sequencer coming from a scene strip is also missing.

This is partially a regression, at least for F12 case. The editing
was already behaving wrong: it was needed to have scene strip to be
actually rendered in preview.

source/blender/editors/space_sequencer/sequencer_add.c

@@ -344,9 +344,6 @@ static int sequencer_add_scene_strip_exec(bContext *C, wmOperator *op)
   BLI_strncpy(seq->name + 2, sce_seq->id.name + 2, sizeof(seq->name) - 2);
   BKE_sequence_base_unique_name_recursive(&ed->seqbase, seq);
 
-  seq->scene_sound = BKE_sound_scene_add_scene_sound(
-      scene, seq, start_frame, start_frame + seq->len, 0);
-
   BKE_sequence_calc_disp(scene, seq);
   BKE_sequencer_sort(scene);