MEXICO CITY (Reuters) – Mexican President Andres Manuel Lopez Obrador on Wednesday said his government was working to keep a lid on undocumented immigration ahead of U.S. elections so that his country is not drawn into the political crossfire. Speaking after Mexican authorities announced they had registered nearly 6,000 undocumented migrants in the country on Friday and Saturday, Lopez Obrador said his government wanted to ensure there was not “an influx of migrants in these days.” Lopez Obrador said the country’s immigration policies were not changing, but stressed that it was important for M…