Obsolete BUILD_BROKEN_DUP_COPY_HEADERS

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Test: treehugger
Change-Id: I1fd5b933372e3ea391c121d265f41c35b832b206
diff --git a/core/config.mk b/core/config.mk
index a297f68..386c64e 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -96,6 +96,7 @@
 $(KATI_obsolete_var TARGET_ROOT_OUT_SBIN,/sbin has been removed, use /system/bin instead)
 $(KATI_obsolete_var TARGET_ROOT_OUT_SBIN_UNSTRIPPED,/sbin has been removed, use /system/bin instead)
 $(KATI_obsolete_var BUILD_BROKEN_PHONY_TARGETS)
+$(KATI_obsolete_var BUILD_BROKEN_DUP_COPY_HEADERS)
 
 # This is marked as obsolete in envsetup.mk after reading the BoardConfig.mk
 $(KATI_deprecate_export It is a global setting. See $(CHANGES_URL)#export_keyword)