ADDIEVILLE, Ill. — Clouds crowded the Illinois sky as Nick Harre walked away from his combine at the peak of harvest to join four fellow farmers in greeting some unlikely visitors.Inside a seed barn, they made their pitch to eight Sri Lankan government officials: Please buy our soybeans.The wooing of such a tiny market underscores the depth of farmers’ problems after losing their biggest customer, China, to a trade war.Sri Lanka bought about 3,000 metric tons of U.S.