MADRID, April 20 (Reuters) - Exiled Equatorial Guinean politician Severo Moto, who lives in Spain, has disappeared and Spanish authorities are concerned he may have been killed, Spanish newspaper El Pais reported on Wednesday. Moto is the leader of a self-styled government in exile and a sworn enemy of Equatorial Guinea's President Teodoro Obiang Nguema Mbasogo, who has accused Moto of being behind a coup attempt in the tiny central African country last year. El Pais and another newspaper, El Mundo, both reported Moto had travelled from Spain to Croatia twice in March, and that since his second trip...