make dependency on directory order-only

Change-Id: I800a7c1ea7ae48252a22ab1dc848fdc5e6f6b3b9

solenv/gbuild/Package.mk

@@ -136,7 +136,7 @@ define gb_Package_add_symbolic_link
 $(call gb_Package__check,$(1))
 $(if $(strip $(3)),,$(call gb_Output_error,gb_Package_add_symbolic_link requires 3 arguments))
 $(call gb_Package_get_target,$(1)) : $$(gb_Package_OUTDIR_$(1))/$(2)
-$$(gb_Package_OUTDIR_$(1))/$(2) : $$(dir $$(gb_Package_OUTDIR_$(1))/$(2)).dir
+$$(gb_Package_OUTDIR_$(1))/$(2) :| $$(dir $$(gb_Package_OUTDIR_$(1))/$(2)).dir
 	rm -f $$@ && ln -s $(3) $$@
 
 $(call gb_Package_get_target,$(1)) : FILES += $$(gb_Package_OUTDIR_$(1))/$(2)