Improved logic when plugin fails to be unloaded.

git-svn-id: http://svn.igniterealtime.org/svn/repos/openfire/branches@9081 b35dd754-fafc-0310-a699-88a17e54d16e

3_3_1_branch/src/plugins/xmldebugger/src/java/org/jivesoftware/openfire/plugin/DebuggerPlugin.java

@@ -59,11 +59,19 @@ public class DebuggerPlugin implements Plugin, PropertyEventListener {
         PropertyEventDispatcher.removeListener(this);
         // Remove filter from filter chain builder
         ConnectionManagerImpl connManager = (ConnectionManagerImpl) XMPPServer.getInstance().getConnectionManager();
+        if (connManager.getSocketAcceptor().getFilterChain().contains("rawDebugger")) {
             connManager.getSocketAcceptor().getFilterChain().remove("rawDebugger");
+        }
+        if (connManager.getSSLSocketAcceptor().getFilterChain().contains("rawDebugger")) {
             connManager.getSSLSocketAcceptor().getFilterChain().remove("rawDebugger");
+        }
         // Remove the filters from existing sessions
+        if (defaultPortFilter != null) {
             defaultPortFilter.shutdown();
+        }
+        if (oldPortFilter != null) {
             oldPortFilter.shutdown();
+        }
 
         // Remove the packet interceptor that prints interpreted XML
         InterceptorManager.getInstance().removeInterceptor(interpretedPrinter);