Change //third_party/usrsctp OWNERS.

Bug: None
Change-Id: Icaee5fb53e4e9542fb8e156f1adbee0abe123cd8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2107982Reviewed-by: Harald Alvestrand <hta@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Mirko Bonadei <mbonadei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#751946}

third_party/usrsctp/OWNERS

-pthatcher@chromium.org
-jiayl@chromium.org
-ldixon@chromium.org
+deadbeef@chromium.org
+hta@chromium.org
 
 # COMPONENT: Internals>Networking