make sepolicy conditional

diff --git a/bliss.mk b/bliss.mk
index b73802e..4ec1556 100644
--- a/bliss.mk
+++ b/bliss.mk
@@ -1,4 +1,4 @@
 $(call inherit-product, vendor/bliss/config/common_full_phone.mk)
-$(call inherit-product, device/lineage/sepolicy/common/sepolicy.mk)
+$(call inherit-product-if-exists, device/lineage/sepolicy/common/sepolicy.mk)
 -include vendor/bliss/build/core/config.mk
 -include vendor/bliss/build/core/apicheck.mk