A masked man armed with an AK-47 and a full magazine of ammunition was reportedly arrested blocks away from the Republican National Convention on Monday night. Homeland Security investigators and Capitol police saw the man approaching near the RNC permitter, blocks from the Fiserv Forum in Milwaukee, a federal law enforcement source told Fox News. The man was wearing a ski mask and hauling a tactical bag containing the weapon and a full magazine, the outlet reported. Milwaukee Police confirmed the report to The Associated Press and said the 21-year-old man was arrested and charges are pending …