The claim and the proof of Theorem 2.9 in Vassilev Trans. Amer. Math. Soc. 363 (2011), no. 1, 37–62 are not correct as stated. We give a correction in Section 1.6. In addition, we correct several typos in the text and strengthen slightly some results of Vassilev Trans. Amer. Math. Soc. 363 (2011), no. 1, 37–62.
Dimiter Vassilev (Fri,) studied this question.