Fixed saving of environment constraints when all are removed on editing.
Fixed saving of environment constraints when all are removed on editing.

mccarrmb/moztrap,bobsilverberg/moztrap,shinglyu/moztrap,shinglyu/moztrap,shinglyu/moztrap,shinglyu/moztrap,bobsilverberg/moztrap,mccarrmb/moztrap,mccarrmb/moztrap,mozilla/moztrap,bobsilverberg/moztrap,mccarrmb/moztrap,mccarrmb/moztrap,mozilla/moztrap,mozilla/moztrap,mozilla/moztrap,bobsilverberg/moztrap,mozilla/moztrap,shinglyu/moztrap