BOSTON — The price of gasoline in Massachusetts is holding steady for Thanksgiving.AAA Northeast said Monday in its weekly survey that self-serve, regular unleaded is averaging $2.53 per gallon. That's unchanged from last week. It's one cent below the national average.AAA projects that nearly 51 million Americans will travel 50 miles or more away from home this Thanksgiving, a 3.3 percent increase over 2016.AAA says the 2017 holiday weekend will see the highest Thanksgiving travel volume since 2005.