fix #1188 fix structure eligibility with strongholds

src/main/java/carpet/mixins/ChunkGenerator_scarpetMixin.java

@@ -1,6 +1,7 @@
 package carpet.mixins;
 
 import carpet.fakes.ChunkGeneratorInterface;
+import net.minecraft.world.biome.Biome;
 import net.minecraft.world.gen.chunk.ChunkGenerator;
 import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.Shadow;
@@ -9,10 +10,16 @@ import org.spongepowered.asm.mixin.Shadow;
 public abstract class ChunkGenerator_scarpetMixin implements ChunkGeneratorInterface
 {
     @Shadow protected abstract void generateStrongholdPositions();
+    @Shadow private static boolean canPlaceStrongholdInBiome(Biome biome) { return true;}
 
-    @Override
+        @Override
     public void initStrongholds()
     {
         generateStrongholdPositions();
     }
+
+    @Override
+    public boolean canPlaceStrongholdInBiomeCM(Biome biome) {
+        return canPlaceStrongholdInBiome(biome);
+    }
 }