Remove unused class

src/main/java/net/floodlightcontroller/devicemanager/internal/APBlockedException.java

-/**
-*    Copyright 2011, Big Switch Networks, Inc. 
-*    Originally created by David Erickson, Stanford University
-* 
-*    Licensed under the Apache License, Version 2.0 (the "License"); you may
-*    not use this file except in compliance with the License. You may obtain
-*    a copy of the License at
-*
-*         http://www.apache.org/licenses/LICENSE-2.0
-*
-*    Unless required by applicable law or agreed to in writing, software
-*    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-*    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-*    License for the specific language governing permissions and limitations
-*    under the License.
-**/
-
-package net.floodlightcontroller.devicemanager.internal;
-
-/**
- * Exception thrown when an attachment point is blocked
- * @author readams
- */
-public class APBlockedException extends Exception {
-
-    private static final long serialVersionUID = 4554154651844610376L;
-
-    public APBlockedException() {
-
-    }
-
-    public APBlockedException(String message) {
-        super(message);
-    }
-
-    public APBlockedException(Throwable cause) {
-        super(cause);
-    }
-
-    public APBlockedException(String message, Throwable cause) {
-        super(message, cause);
-    }
-
-}