Mark anchor destinations valid if they pass location checks

This commit closes portals bug #92

src/main/java/com/onarandombox/MultiverseCore/destination/AnchorDestination.java

@@ -80,6 +80,7 @@ public class AnchorDestination implements MVDestination {
         if (!parsed.get(0).equalsIgnoreCase(this.getIdentifier())) {
             this.isValid = false;
         }
+        this.isValid = true;
     }
 
     @Override