Fix SideEffectSet.none() being the default set (#1620)

* Fix SideEffectSet.none() being the default set

* Remove the unnecessary private empty constructor for SideEffectSet

* Back to ImmutableMap.of

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffectSet.java

@@ -30,19 +30,15 @@
 import java.util.stream.Collectors;
 
 public class SideEffectSet {
-    private static final SideEffectSet DEFAULT = new SideEffectSet(
-            Arrays.stream(SideEffect.values()).collect(Collectors.toMap(Function.identity(), SideEffect::getDefaultValue))
+    private static final SideEffectSet DEFAULT = new SideEffectSet(ImmutableMap.of());
+    private static final SideEffectSet NONE = new SideEffectSet(
+        Arrays.stream(SideEffect.values()).collect(Collectors.toMap(Function.identity(), state -> SideEffect.State.OFF))
     );
-    private static final SideEffectSet NONE = new SideEffectSet();
 
     private final Map<SideEffect, SideEffect.State> sideEffects;
     private final Set<SideEffect> appliedSideEffects;
     private final boolean appliesAny;
 
-    private SideEffectSet() {
-        this(ImmutableMap.of());
-    }
-
     public SideEffectSet(Map<SideEffect, SideEffect.State> sideEffects) {
         this.sideEffects = Maps.immutableEnumMap(sideEffects);