FE4: Units with major holy blood who get the same type as Sigurd ending up with minor blood instead of a different major blood

Seed details [here](https://www.dropbox.com/s/v90p5zy17pa6bw7/FE4%20rando%2052.html?dl=0). This changelog is the same as in other issues. This happened to both Brigid and Deirdre in this seed.