A Mexican-British man, whose family alleged he was arrested in Qatar for being gay, has been sentenced to prison but can leave the country after paying a fine, the Mexican government said on Tuesday. Manuel Guerrero, an airline employee, was detained in February in the Gulf state, where homosexuality is illegal. On Tuesday, a Qatari judge sentenced Guerrero to six months in prison, although he will not have to serve the time, Mexico’s foreign ministry said, without saying why. It said that Guerrero, who had already been granted provisional release, would be allowed to leave Qatar after paying …