Silence a crash in update_engine when dns resolution fails am: 96ff7b28c6

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/3351181

Change-Id: I4186dd5b9dbc06036a7a7b57f97c4a0fdb518a11
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>