By Jonathan Saul LONDON, July 9 (Reuters) - Oil tanker traffic through the Strait of Hormuz was at a near standstill on Thursday, according to data and sources, as shipping risks escalated after the U.S. renewed airstrikes on Iran, triggering retaliation by Tehran in the Gulf. Just two tankers had so far sailed through the strait in the early hours of Thursday. They included the crude supertanker Berg 1, which had loaded at Iran's Kharg Island and is subject to U.S. sanctions, according to analy