SYDNEY, June 19 (Reuters) - The Australian Energy Market Operator (AEMO) said a fire that ripped through a New South Wales power station on Saturday will not affect electricity supply, already snarled by an energy crisis in the country's east. Power supply in Australia's heavily populated east has been stretched since mid-May as around 25% of the market's 23,000 megawatt (MW) of coal-fired capacity has...