Cleanup OWNERS

Bruce Chen hasn't been with us since December.

Test: N/A
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Id62e55244208c4db70c178d2c72bd904226acbf9
diff --git a/OWNERS_core_networking b/OWNERS_core_networking
index 172670e..6d17476 100644
--- a/OWNERS_core_networking
+++ b/OWNERS_core_networking
@@ -1,4 +1,3 @@
-chenbruce@google.com
 chiachangwang@google.com
 cken@google.com
 huangaaron@google.com