Remove explicit reference myself from domain_reliability/OWNERS.

I was added as backup OWNER before net/OWNERS as here. Now that net/OWNERS is
here, remove explicit reference to myself, so this is spread between all
net/OWNERS.

Bug: none
Change-Id: Id27d6b73e24708fa0eb9c903621f9d40c7d20956
Reviewed-on: https://chromium-review.googlesource.com/1186983Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: David Benjamin <davidben@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585507}

components/domain_reliability/OWNERS

-davidben@chromium.org
-
 file://net/OWNERS
 
 per-file quic_error_mapping*=rch@chromium.org