A Kenyan court today found two men guilty of helping al Qaeda-linked militants launch a 2013 assault on a Nairobi shopping mall in which gunmen killed at least 67 people. A third man who also faced charges under the country's terrorism prevention act was acquitted on all charges. The trial is the only prosecution Kenya has mounted so far over the attack by gunmen from the Somali militant group al Shabaab on Nairobi's Westgate shopping mall, at the time seen as a symbol of the East African country's growing prosperity. It was the worst attack by Islamist militants in Kenya,…