Testimony by spouse after attack on character or conduct. In all civil actions brought by either the husband or wife, either the husband or

§ 5926.  Testimony by spouse after attack on character or conduct. In all civil actions brought by either the husband or wife, either the husband or the wife shall be a competent witness in rebuttal, when his or her character or conduct is attacked upon the trial thereof, but only in regard to the matter of his or her character or conduct.