Fix for [#22668] Adding sequencer color strip fails when sound strip selected.

Hi,

I've written a patch to fix this issue. Since the Effect Strip
"Color" doesn't need any input sequences, there is
no need to output a warning when adding this effect while other
sequences are selected. My fix let's all Effect Strips that don't
need input sequences pass the warning "Can't apply effects
to audio sequence strips". I think this is fair.

-Konrad

source/blender/editors/space_sequencer/sequencer_edit.c

@@ -621,7 +621,7 @@ int seq_effect_find_selected(Scene *scene, Sequence *activeseq, int type, Sequen
 
 	for(seq=ed->seqbasep->first; seq; seq=seq->next) {
 		if(seq->flag & SELECT) {
-			if (seq->type == SEQ_SOUND) {
+			if (seq->type == SEQ_SOUND && get_sequence_effect_num_inputs(type) != 0) {
 				*error_str= "Can't apply effects to audio sequence strips";
 				return 0;
 			}