NAIROBI, Kenya — Kenyan opposition leader Raila Odinga on Tuesday shocked the country by withdrawing his candidacy for the fresh presidential election ordered by the Supreme Court, saying the election commission has not made changes to avoid the “irregularities and illegalities” cited in the nullified August vote. Odinga’s legal challenge of vote-rigging had led the court to nullify the election that President Uhuru Kenyatta won with 54 percent of ballots.