(1) The statements of a petition for dissolution of marriage concerning the residence of the parties and irretrievable breakdown of the marriage shall not be taken as true because of the respondent's failure to deny the statements, and the facts as to residence of the parties must be proved by one (1) or more credible witnesses.
(2) The petitioner or respondent in an action for dissolution of marriage may be considered a credible witness, within the meaning of subsection (1) of this section, to be utilized in order to prove residency of the parties. The provisions of this subsection shall be retroactive in effect.