Silence a crash in update_engine when dns resolution fails am: 96ff7b28c6 am: ff5a81b8e6

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

Change-Id: Ic00252287a4e7175f0ff1131eab4affcc7310695
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>