Freestyle: Fix for the active line set index possibly invalidated after deleting a line set.

source/blender/blenkernel/intern/freestyle.c

@@ -207,6 +207,7 @@ bool BKE_freestyle_lineset_delete(FreestyleConfig *config, FreestyleLineSet *lin
 	}
 	BLI_remlink(&config->linesets, lineset);
 	MEM_freeN(lineset);
+	BKE_freestyle_lineset_set_active_index(config, 0);
 	return true;
 }
 

source/blender/freestyle/intern/blender_interface/FRS_freestyle.cpp

@@ -712,7 +712,6 @@ void FRS_delete_active_lineset(FreestyleConfig *config)
 
 	if (lineset) {
 		BKE_freestyle_lineset_delete(config, lineset);
-		BKE_freestyle_lineset_set_active_index(config, 0);
 	}
 }