RENO - A federal judge has agreed to let the U.S. Bureau of Land Management resume the roundup of dozens of wild mustangs in northern Nevada but says she remains concerned about critics' complaints the agency is treating the animals inhumanely.U.S District Judge Miranda Du explained Thursday she was granting the government's request to lift an emergency injunction that halted the roundup last week because opponents had failed to prove the agency lacked authority to remove the mustangs from the high desert near the Idaho line.The judge said she intended to issue a formal order on Friday but hadn't decided …