Minor improvements to the server side CUI

worldedit-core/src/main/java/com/sk89q/worldedit/regions/selector/CuboidRegionSelector.java

@@ -249,6 +249,8 @@ public class CuboidRegionSelector implements RegionSelector, CUIRegion {
     public void clear() {
         position1 = null;
         position2 = null;
+        region.setPos1(BlockVector3.ZERO);
+        region.setPos2(BlockVector3.ZERO);
     }
 
     @Override