fixing scoreboard API

src/main/java/carpet/mixins/ScoreboardObjective_scarpetMixin.java

@@ -3,10 +3,11 @@ package carpet.mixins;
 import net.minecraft.scoreboard.ScoreboardCriterion;
 import net.minecraft.scoreboard.ScoreboardObjective;
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Mutable;
 import org.spongepowered.asm.mixin.gen.Accessor;
 
 @Mixin(ScoreboardObjective.class)
 public interface ScoreboardObjective_scarpetMixin {
-    @Accessor("criterion")
+    @Mutable @Accessor("criterion")
     void setCriterion(ScoreboardCriterion criterion);
 }