Add missing comma in ozone_scenic watchlist

TBR=wez@chromium.org

Change-Id: I68e17769dec2d0bdc92c7cad609b243b78aec69b
Reviewed-on: https://chromium-review.googlesource.com/c/1325071
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606239}

WATCHLISTS

@@ -2330,7 +2330,7 @@
               'msisov@igalia.com',
               'ozone-reviews@chromium.org'],
     'ozone_scenic': ['dworsham@google.com',
-                     'rjkroege@chromium.org'
+                     'rjkroege@chromium.org',
                      'sergeyu@chromium.org',
                      'spang+watch@chromium.org',
                      'wez@chromium.org'],