Suppress error message when gc is cleaned already [ci skip]

Author: nobu

template/Makefile.in

@@ -569,10 +569,10 @@ ext/distclean ext/realclean .bundle/distclean .bundle/realclean::
 	@$(RMALL) $(tooldir)/bunlder/*.lock $(srcdir)/.bundle
 
 gc/clean gc/distclean gc/realclean::
-	- for gc in gc/*/; do ($(CHDIR) $$gc && exec $(MAKE) TARGET_SO_DIR=./ $(@F)); done || $(NULLCMD)
+	- $(CHDIR) gc 2> /dev/null && for gc in */; do ($(CHDIR) $$gc && exec $(MAKE) TARGET_SO_DIR=./ $(@F)); done || $(NULLCMD)
 
 gc/distclean gc/realclean::
-	- for gc in gc/*/; do $(RMDIR) $$gc; done || $(NULLCMD)
+	- $(CHDIR) gc 2> /dev/null && for gc in */; do $(RMDIR) $$gc; done || $(NULLCMD)
 
 clean-enc distclean-enc realclean-enc:
 	@test -f "$(ENC_MK)" || exit 0; \