[ISSUE apache#4859] Remove unused variable responseEventMeshCommand in SendSyncMessageProcessor#processRequest (apache#4860)

Author: rohit-satya

eventmesh-runtime/src/main/java/org/apache/eventmesh/runtime/core/protocol/http/processor/SendSyncMessageProcessor.java

@@ -73,7 +73,6 @@ public SendSyncMessageProcessor(final EventMeshHTTPServer eventMeshHTTPServer) {
     public void processRequest(final ChannelHandlerContext ctx, final AsyncContext<HttpCommand> asyncContext)
         throws Exception {
 
-        HttpCommand responseEventMeshCommand;
         HttpCommand request = asyncContext.getRequest();
         final String localAddress = IPUtils.getLocalAddress();
         final String remoteAddr = RemotingHelper.parseChannelRemoteAddr(ctx.channel());