By Harm Venhuizen THE ASSOCIATED PRESS MADISON, Wis. (AP)- A federal judge signaled Thursday he will not force an energy company to shut down an oil pipeline in northern Wisconsin, deSpite arguments from a Nativ* American tribe that the line is at immediate risk of being exposed by erosion and rupturing on reservation land. The Bad River Band of Lake Superior Chippewa asked U.S. District Judge William Conley last week to issue an emergency ruling forcing Enbridge to shut down the Line 5 pipeline after large chunks of riverbank running alongside it were washed away. But Conley voiced frustration with the tribe at Thursday’s hearing for not allowing Enbridge to reinforce the land around the pipeline. “The band has not helped itself by refusing to take any steps to prevent…