An eerie calm prevails at the FleetCenter By David R. Guarino Thursday, June 24, 2004 With convention construction already $5 million over budget and three days delayed due to a picket line, all was amazingly quiet inside the FleetCenter yesterday - 33 days from DNC D-Day. Convention organizers and Mayor Thomas M. Menino say construction's on schedule. But, to the naked eye, the FleetCenter is far from ready for Sen. John F. Kerry's big event. Workers have taken out seats to make room for the convention stage and steel has been added to the ceiling to help light the ceremonies....