The winning positions are:

2.......1.......1.......1
4.......4.......2.......1.......5.......4.......3.......2
6.......5.......3.......1.......5.......4.......3.......2

The player who plays first always wins. It's enough he begins picking 1 matchstick from any row, like below:

2.......3.......3
5.......4.......5
7.......7.......6

In this way, he always will can force the winning positions above.