In all civil actions and special proceedings where the defendants were served with summons and judgment thereafter entered, or any final decree made, and said judgments or decrees shall not be invalidated by reason of the fact that the summons, although designated an alias or pluries summons, was not actually such: Provided, that this section shall not apply where the first summons was issued more than five years preceding March 6, 1943. (1943, c. 532.)