Cook County Board President Toni Preckwinkle (left) attends a news conference last year to endorse then mayoral candidate Brandon Johnson outside City Hall in the Loop.Pat Nabong/Sun-Times A divided City Council committee agreed Monday to slap another $70 million Band-Aid on Chicago’s migrant crisis after behind-the-scenes lobbying by County Board President Toni Preckwinkle and others.Preckwinkle was among those calling recalcitrant City Counci…