By Nina de Vries FREETOWN, Feb 1 (Reuters) - It has no fence around it or any grass on its pitch but the Kingtom Oval cricket ground represents for many inhabitants of Sierra Leone's capital Freetown a reminder of happier times before the West African country's brutal civil war. The only cricket ground to have survived the 11-year conflict, which killed some 50,000 people and devastated the impoverished country's infrastructure, the Oval is now the focus of an attempt to revive the sport.