The board overseeing Maryland's health exchange voted unanimously Tuesday evening to scrap its dysfunctional website and adopt software developed by Deloitte Consulting and used by the more successful health exchange in Connecticut. The software is free for Maryland to use but Health Secretary Joshua M. Sharfstein will negotiate an emergency $40 million to $50 million contract with the software company to develop the site. Isabel FitzGerald, secretary of the state's Department of Information Technology, who stepped in to help fix the exchange, will oversee the project. The move comes a day after open enrollment under the federal Affordable Care Act ended Monday, when consumers still were having trouble with the glitch-prone website. Maryland is the first state with a troubled website to switch to another system.