worker: Fix assertIn check (parameters were swapped).
worker: Fix assertIn check (parameters were swapped).

Before this, the test checked if the empty string (stdout) is in the (actually) wanted text. This always succeeded even if it should not have.
applift/vitess,mahak/vitess,erzel/vitess,dumbunny/vitess,vitessio/vitess,applift/vitess,rnavarro/vitess,dcadevil/vitess,sougou/vitess,HubSpot/vitess,tinyspeck/vitess,enisoc/vitess,mattharden/vitess,dumbunny/vitess,HubSpot/vitess,applift/vitess,rnavarro/vitess,davygeek/vitess,dumbunny/vitess,alainjobart/vitess,rnavarro/vitess,pivanof/vitess,erzel/vitess,dcadevil/vitess,tirsen/vitess,mahak/vitess,rnavarro/vitess,vitessio/vitess,vitessio/vitess,mattharden/vitess,enisoc/vitess,mapbased/vitess,dumbunny/vitess,davygeek/vitess,HubSpot/vitess,pivanof/vitess,mattharden/vitess,pivanof/vitess,dcadevil/vitess,dcadevil/vitess,rnavarro/vitess,alainjobart/vitess,HubSpot/vitess,tinyspeck/vitess,dcadevil/vitess,alainjobart/vitess,tirsen/vitess,alainjobart/vitess,tirsen/vitess,HubSpot/vitess,mahak/vitess,vitessio/vitess,sougou/vitess,tirsen/vitess,mahak/vitess,erzel/vitess,tirsen/vitess,dumbunny/vitess,tirsen/vitess,pivanof/vitess,enisoc/vitess,dumbunny/vitess,mahak/vitess,dcadevil/vitess,rnavarro/vitess,mattharden/vitess,davygeek/vitess,alainjobart/vitess,rnavarro/vitess,HubSpot/vitess,HubSpot/vitess,HubSpot/vitess,vitessio/vitess,vitessio/vitess,alainjobart/vitess,mahak/vitess,rnavarro/vitess,mattharden/vitess,rnavarro/vitess,mattharden/vitess,erzel/vitess,davygeek/vitess,pivanof/vitess,applift/vitess,erzel/vitess,mattharden/vitess,mattharden/vitess,erzel/vitess,mapbased/vitess,tinyspeck/vitess,tirsen/vitess,enisoc/vitess,mattharden/vitess,erzel/vitess,sougou/vitess,applift/vitess,mahak/vitess,enisoc/vitess,tirsen/vitess,vitessio/vitess,mapbased/vitess,dumbunny/vitess,tinyspeck/vitess,pivanof/vitess,dumbunny/vitess,mapbased/vitess,erzel/vitess,applift/vitess,mapbased/vitess,alainjobart/vitess,applift/vitess,davygeek/vitess,applift/vitess,tinyspeck/vitess,dcadevil/vitess,enisoc/vitess,applift/vitess,sougou/vitess,mapbased/vitess,tinyspeck/vitess,tinyspeck/vitess,mapbased/vitess,vitessio/vitess,sougou/vitess,mapbased/vitess,dumbunny/vitess,erzel/vitess,sougou/vitess,alainjobart/vitess,enisoc/vitess,applift/vitess,sougou/vitess,erzel/vitess,mahak/vitess,davygeek/vitess,davygeek/vitess,pivanof/vitess,mapbased/vitess,pivanof/vitess,pivanof/vitess,mattharden/vitess,tirsen/vitess,dumbunny/vitess,mapbased/vitess,sougou/vitess