[Bug Fix] Instrument Mods should not affect spells that change model size. (#2072)

Instrument Mods should not affect spells that change model size.

common/spdat.cpp

@@ -1474,6 +1474,8 @@ bool IsInstrumentModAppliedToSpellEffect(int32 spell_id, int effect)
 		case SE_SeeInvis:
 		case SE_Levitate:
 		case SE_WaterBreathing:
+		case SE_ModelSize:
+		case SE_ChangeHeight:
 			return false;
 		default:
 			return true;