HBO has seen this one before. On Sunday night, users of its HBO Go streaming service who showed up at 9pm eastern, so they could watch the much-anticipated season premiere of “Game of Thrones,” got error messages instead. HBO sent out apologetic tweets, and eventually got things running again. This was a repeat from March, when HBO Go users who wanted to watch the much-anticipated season finale of “True Detective” went through the same experience. The two episodes invite embarrassing comparisons to Netflix, which streams video to some 30 million customers, and doesn’t generate the same kind of headlines for its outages. The fact that Netflx isn’t showing the same show — at the same time, to many people — is relevant, but that kind of nuance doesn’t usually show up in 140 characters.