Correct event reference

.taskcluster.yml

@@ -52,7 +52,7 @@ tasks:
                   A subset of WPT's "${chunk[0]}" tests (chunk number ${chunk[1]}
                   of ${chunk[2]}), run in the ${browser.channel} release of
                   ${browser.name}.
-                owner: ${event.pusher.email}
+                owner: ${event.sender.login}
                 source: ${event.repository.url}
               payload:
                 image: jugglinmike/web-platform-tests:0.17