Vowing to Live in Eretz Yisroel

If a woman living outside of Eretz Yisroel pronounced a vow that she will go and live in Eretz Yisroel; at the time of her vow, it was not dangerous to live there, but later, there was a fear of war. Is the husband allowed to annul her vow?

Perhaps this question would be dependent on whether there is a mitzvah nowadays to live in Eretz Yisroel. Rabbeinu Chaim Kohen and Tosfos (110b) maintain that there is no mitzvah. The Ramban and other Rishonim disagree and hold that there is a mitzvah. The Chidah in Birkei Yosef discusses if this is regarded as a vow that involves personal affliction or not.