update ajp connector when it was in using

hi,I found an issue like this:
 in every application server that use embed tomcat, when the ajp connector was in using, just like blow code:
```
  while (!error && !endpoint.isPaused()) {
            // Parsing the request header
            try {
                // Set keep alive timeout if enabled
                if (keepAliveTimeout > 0) {
                    socket.getSocket().setSoTimeout(keepAliveTimeout);
                }
                // Get first message of the request
                if (!readMessage(requestHeaderMessage)) {
                    // This means a connection timeout
                    break;
                }
                //add start    ajp connector was updated when it was in using this will break
                if(endpoint.isUpdated()) {
                	break;
                }//add end
```
then update the ajp connector. Now the connector will destory and recreate. But in above code, the connection was still in use. When request coming, a NullPointerException will throw in code ```adapter.log(request,response,0);```
```
          if (!error) {
                // Setting up filters, and parse some request headers
                rp.setStage(com.tongweb.web.oro.Constants.STAGE_PREPARE);
                try {
                    prepareRequest();
                } catch (Throwable t) {
                    ExceptionUtils.handleThrowable(t);
                    log.debug(sm.getString("ajpprocessor.request.prepare"), t);
                    // 400 - Internal Server Error
                    response.setStatus(400);
                    adapter.log(request, response, 0);
                    error = true;
                }
            }
```

And I think add an attribute, when it was updated, then break and use a new connection will solve this problem.