By Ulf Laessing TOBRUK, Libya, Sept 22 (Reuters) - Libya's elected parliament approved on Monday a new cabinet proposed by Prime Minister Abdullah al-Thinni, a parliamentary spokesman said. The House of Representatives agreed on a second cabinet list after rejecting last week an initial a 16-member lineup as too large, spokesman Faraj Hashem said. The new cabinet has only 13 ministers and ** oil minister, lawmakers said. The vital oil sector will be run by state firm National Oil Corp (**C). ...