Add nharper to net/quic/OWNERS

Change-Id: I88da2498df4c837cc037f452bf0b64c1c373e157
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699142
Commit-Queue: David Schinazi <dschinazi@chromium.org>
Commit-Queue: Nick Harper <nharper@chromium.org>
Reviewed-by: Nick Harper <nharper@chromium.org>
Cr-Commit-Position: refs/heads/master@{#676627}

net/quic/OWNERS

+nharper@chromium.org
 rch@chromium.org
 zhongyi@chromium.org