CAIRO, Aug 5 (Reuters) - A Suez Canal tugboat sank on Saturday and one of its crew was missing after it collided with a Hong Kong-flagged LPG tanker though shipping traffic in the strategically important waterway was largely unaffected, the canal authority said. Convoys of ships passing through the canal from the north were not affected, while the passage of ships travelling from the south returned to normal by about midnight on Saturday, Suez Canal Authority (SCA) said in a statement. See here for a complete list of exchanges and delays