vtgate/buffer: Increase wait duration in unit test to reduce flakyness.
vtgate/buffer: Increase wait duration in unit test to reduce flakyness.

On my Laptop I see the test failing after hundreds of attempts when the machine is under load. A higher timeout helps here.

rnavarro/vitess,tinyspeck/vitess,alainjobart/vitess,HubSpot/vitess,pivanof/vitess,vitessio/vitess,applift/vitess,enisoc/vitess,pivanof/vitess,pivanof/vitess,applift/vitess,HubSpot/vitess,davygeek/vitess,pivanof/vitess,tinyspeck/vitess,alainjobart/vitess,applift/vitess,alainjobart/vitess,pivanof/vitess,tirsen/vitess,dcadevil/vitess,tinyspeck/vitess,applift/vitess,dcadevil/vitess,pivanof/vitess,rnavarro/vitess,alainjobart/vitess,vitessio/vitess,HubSpot/vitess,applift/vitess,applift/vitess,alainjobart/vitess,enisoc/vitess,tirsen/vitess,applift/vitess,rnavarro/vitess,sougou/vitess,HubSpot/vitess,mattharden/vitess,pivanof/vitess,enisoc/vitess,sougou/vitess,mahak/vitess,tirsen/vitess,vitessio/vitess,tinyspeck/vitess,HubSpot/vitess,applift/vitess,davygeek/vitess,rnavarro/vitess,davygeek/vitess,tirsen/vitess,dcadevil/vitess,HubSpot/vitess,sougou/vitess,rnavarro/vitess,sougou/vitess,tinyspeck/vitess,alainjobart/vitess,mattharden/vitess,applift/vitess,rnavarro/vitess,sougou/vitess,vitessio/vitess,mattharden/vitess,HubSpot/vitess,rnavarro/vitess,tinyspeck/vitess,alainjobart/vitess,rnavarro/vitess,mattharden/vitess,sougou/vitess,mattharden/vitess,mattharden/vitess,davygeek/vitess,tinyspeck/vitess,davygeek/vitess,enisoc/vitess,applift/vitess,mahak/vitess,rnavarro/vitess,tirsen/vitess,HubSpot/vitess,enisoc/vitess,tirsen/vitess,davygeek/vitess,pivanof/vitess,mahak/vitess,sougou/vitess,vitessio/vitess,tirsen/vitess,pivanof/vitess,mattharden/vitess,enisoc/vitess,mattharden/vitess,mahak/vitess,dcadevil/vitess,sougou/vitess,tirsen/vitess,vitessio/vitess,enisoc/vitess,dcadevil/vitess,davygeek/vitess,mahak/vitess,dcadevil/vitess,mattharden/vitess,vitessio/vitess,mahak/vitess,dcadevil/vitess,mahak/vitess,vitessio/vitess,mattharden/vitess,alainjobart/vitess,mahak/vitess,tirsen/vitess