A federal judge in southern Illinois ruled Friday that the registration process for guns grandfathered in under the state’s sweeping ban on many high-powered weapons and high-capacity magazines should remain in place while litigation over the law continues to be hashed out in court. The ruling had been expected after U.S. District Judge Stephen McGlynn, during a hearing earlier this month, indicated that he was not inclined to issue an injunction that would put off the Jan. 1 deadline for Illinois residents to register guns covered by the ban. His decision means Illinoisans have a little more …