Check for either TCP or UnixSocket when starting mysql plugin server
Check for either TCP or UnixSocket when starting mysql plugin server

* Only TCP port was set.
* Only Unix socket was set.
* Both were set.

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