Don't leak credentials in debug_info

No need to dump Gmail OAuth client_secret, refresh_token, and
access_token in the debug ZIP in plaintext.

cps/config_sql.py

@@ -326,7 +326,9 @@ class ConfigSQL(object):
     def to_dict(self):
         storage = {}
         for k, v in self.__dict__.items():
-            if k[0] != '_' and not k.endswith("_e") and not k == "cli" and 'api' not in k.lower():
+            if k[0] != '_' and not k.endswith("_e") and not k == "cli" \
+                    and 'api' not in k.lower() and 'token' not in k.lower() \
+                    and 'secret' not in k.lower()
                 storage[k] = v
         return storage