By David Shepardson WASHINGTON (Reuters) -The United States on Friday reopened two rail crossings between Texas and Mexico vital for exports, five days after their closure in response to increased migrant traffic, and new U.S. data showed migrant numbers at the southern U.S. border remained high last month. U.S. Customs and Border Protection (CBP) said operations resumed on Friday afternoon at the international railway crossing bridges in Eagle Pass and El Paso, Texas. The closures had dismayed railroads, the agriculture industry and some lawmakers concerned by the loss of exports. The White H…