FREETOWN, July 1 (Reuters) - Sierra Leone's main opposition party said it had decided to formally reject the results of the national election won by President Julius Maada Bio, citing "glaring irregularities", and called for a rerun of the June 24 poll. Bio was re-elected for a second term with 56% of the vote, narrowly avoiding a run-off against main rival Samura Kamara of the opposition All People's Congress (APC). But Kamara has questioned the official