Fix WATCHLIST (missing quotes)

TBR=solenberg@webrtc.org
NOTRY=true

Review URL: https://codereview.webrtc.org/1896703002

Cr-Commit-Position: refs/heads/master@{#12389}
diff --git a/WATCHLISTS b/WATCHLISTS
index 3742e7e..38a0cf9 100644
--- a/WATCHLISTS
+++ b/WATCHLISTS
@@ -114,7 +114,7 @@
              'pbos@webrtc.org',
              'solenberg@webrtc.org',
              'stefan@webrtc.org'],
-    'media': [solenberg@webrtc.org],
+    'media': ['solenberg@webrtc.org'],
     'video': ['mflodman@webrtc.org',
               'pbos@webrtc.org',
               'perkj@webrtc.org',