SHARM EL-SHEIKH, Egypt (Reuters) - France said on Monday it attached little credence to a previously unknown Islamic group's claim to have brought down a plane that crashed off Egypt, killing 133 French tourists and 15 other people. Egypt again defended the safety record of Flash Airlines, operators of the Boeing 737 that plunged into the Red Sea on Saturday, but Switzerland issued a fresh statement that it had banned the Egyptian company from its airspace on safety grounds. French civil aviation authority head Michel Wachenheim said France's own checks on the doomed plane had showed "nothing abnormal." An anonymous...