Any widow receiving a pension under this chapter who shall become a resident citizen of another state shall be dropped from the pension roll of this state, and the county department of human resources is expressly prohibited from delivering the pension warrant to any payee who is at the time of such delivery a resident citizen of another state. On the return of any such pensioner to the state and the reestablishment by her of residence in this state, the name of such pensioner shall be restored to the pension roll; provided, however, that if a pensioner temporarily removes to another state, but does not abandon her legal residence in this state, such pensioner shall not be dropped from the pension roll but shall be retained thereon, and her warrant shall be sent by registered or certified mail to the temporary address of such pensioner, return receipt requested.