Crystal structure of catena-poly[(μ2-2,5-di(pyridin-3-yl)-1,3,4-thiadiazole-κ2N:N′)-bis(2,5-di(pyridin-3-yl)-1,3,4-thiadiazole-κ1N)-bis(thiocyanato-κ1N)cobalt(II)], C38H24CoN14S5