Fix synapse_port_db failure (fixes #1902)

See https://matrix.to/#/!cURbafjkfsMDVwdRDQ:matrix.org/$148686272020hCgRD:potatofrom.space

Signed-off-by: Kevin Liu <kevin@potatofrom.space>

scripts/synapse_port_db

@@ -40,6 +40,7 @@ BOOLEAN_COLUMNS = {
     "presence_list": ["accepted"],
     "presence_stream": ["currently_active"],
     "public_room_list_stream": ["visibility"],
+    "device_list_outbound_pokes": ["sent"],
 }