The value of the contract is the profit it represents. As an example, suppose I sign a contract to sell an asset in one year for $3$. I can buy the asset today for $2$ (the current price) and interest is $5\%$ for a year. If I buy the asset today, I pay $2$ for the asset plus $0.10$ interest, so I have a profit of $0.90$. That is the value of the contract. What the text is saying is that you should expect the forward price to be $2.10$ so there is no profit to be made. If the forward price were lower there would be a profit to be made by selling today and buying back in a year.