cmd/tsconnect/wasm: add missing tstun.Wrapper.Start call
It's required as of the recent 5297bd2cff8e.
Updates #7894
Updates #9394 (sure would be nice)
Change-Id: Id6672408dd8a6c82dba71022c8763e589d789fcd
Signed-off-by: Brad Fitzpatrick <[email protected]>