Update asynchronous-programming.rst (#1200)
Update asynchronous-programming.rst (#1200)

line 25: small grammar edit
crossbario/autobahn-python,oberstet/autobahn-python,oberstet/autobahn-python,oberstet/autobahn-python,crossbario/autobahn-python,crossbario/autobahn-python,tavendo/AutobahnPython