Fix #4207: Scenario Editor freezes the game

Recent commits have caused the sprite spatial index to be uninitialised for the editor modes. Call 
eset_sprite_spatial_index within 
eset_sprite_list as the two come hand in hand.

src/world/sprite.c

@@ -128,6 +128,8 @@ void reset_sprite_list()
 	}
 
 	gSpriteListCount[SPRITE_LIST_NULL] = MAX_SPRITES;
+
+	reset_sprite_spatial_index();
 }
 
 /**