The Ultimate Fighting Championship is headed to Boston on Aug. 17 for its sophomore effort in the city. UFC on Fox Sports 1: Shogun vs. Sonnen is slated for the TD Gardens and is set to serve as featured programming for the launch of Fox’s new nationwide sports channel, Fox Sports 1. A Boston Herald report on Tuesday brought to light an issue that UFC officials faced in regards to all mixed martial arts competitors in Massachusetts being required to have a valid Social Security number, even foreign-born participants. The report noted that the UFC was seeking an exemption from the law, and suggested that the event could be cancelled altogether if things weren’t worked out. The report jumped the gun a good bit, as UFC sources assured MMAWeekly.com on Tuesday that the event “is not in danger, and we’re working on getting visas and social security numbers. Tickets are on sale and moving well.” The UFC later in the day offered an official company statement, again assuring that the Aug.