test_selector_events: remove duplicate call to _on_handshake() method
test_selector_events: remove duplicate call to _on_handshake() method

The _SelectorSslTransport constructor already calls it.

1st1/asyncio,manipopopo/asyncio,Martiusweb/asyncio,gsb-eng/asyncio,fallen/asyncio,fallen/asyncio,manipopopo/asyncio,ajdavis/asyncio,gvanrossum/asyncio,gsb-eng/asyncio,ajdavis/asyncio,haypo/trollius,gvanrossum/asyncio,vxgmichel/asyncio,fallen/asyncio,gsb-eng/asyncio,Martiusweb/asyncio,1st1/asyncio,gvanrossum/asyncio,jashandeep-sohi/asyncio,Martiusweb/asyncio,jashandeep-sohi/asyncio,haypo/trollius,vxgmichel/asyncio,1st1/asyncio,manipopopo/asyncio,haypo/trollius,jashandeep-sohi/asyncio,vxgmichel/asyncio,ajdavis/asyncio