Ex-con Frank Citro wants to get out of Nevada’s Black Book. If history is any indication, the streetwise singer faces an uphill battleA few years ago, Frank Citro Jr. wanted to take his family to see Jersey Boys on the Strip. Now 73, the Jersey City native knew the original band that inspired the show, and had become close with singer Travis Cloer, who played Frankie Valli in the Vegas gig.Citro sent his wife and two grown children on without him; he knew he couldn’t go. He’s banned for life from setting foot inside any of Nevada’s 220 statewide gaming rooms. Citro belongs to a notorious club that harkens back to the historic annals of Las Vegas public life. It’s Nevada’s Black Book, officially known as the “Excluded Person’s List,” an index of undesirables, felons, and parolees blackballed by state casino regulators. For 27 years, Citro hasn’t been able to enter a casino. That means no shows, no fancy dinners, or nights out gambling with friends. The avid doo-wop s