[diablo] Fix shrine rng (#4529)

This bug was less sever in Diablo then Hellfire as it didn't fully initialize the object leading to them sometimes getting garbage as the RNG seed, but it was never working correctly.

Source/objects.cpp

@@ -1219,6 +1219,7 @@ void AddBarrel(Object &barrel)
 
 void AddShrine(int i)
 {
+	Objects[i]._oRndSeed = AdvanceRndSeed();
 	bool slist[NumberOfShrineTypes];
 
 	Objects[i]._oPreFlag = true;