tasks.gather: Fix docstring
tasks.gather: Fix docstring

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