The economy is strong - unemployment is low...seems just the equation that MIGHT mean the end for the nation's food shelves. But many food shelf operators say it's likely they'll serve even MORE people this year because of welfare reform. There have already been reports of a jump in the number of new clients looking for food. At this point, the connection isn't conclusive, but food shelf operators believe they are in a unique position to gauge the effects of welfare reform. Minnesota Public Radio's Gretchen Lehmann reports. It's the beginning of the month, the only down time here at St. Francis Food Shelf in Little Falls. By month's end, when paychecks have been stretched thin, there will be a long line of people waiting to pick up their monthly allot