optimize code

spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-seata/src/main/java/com/alibaba/cloud/seata/web/SeataHandlerInterceptor.java

@@ -47,8 +47,6 @@ public class SeataHandlerInterceptor implements HandlerInterceptor {
 	@Override
 	public boolean preHandle(HttpServletRequest request, HttpServletResponse response,
 			Object handler) {
-        Object xidStatus = request.getAttribute(BIND_XID);
-        if (null == xidStatus || !(boolean)xidStatus) {
         String xid = RootContext.getXID();
         String rpcXid = request.getHeader(RootContext.KEY_XID);
         if (log.isDebugEnabled()) {
@@ -62,7 +60,6 @@ public class SeataHandlerInterceptor implements HandlerInterceptor {
                 log.debug("bind {} to RootContext", rpcXid);
             }
         }
-        }
         return true;
 	}
 
@@ -86,7 +83,6 @@ public class SeataHandlerInterceptor implements HandlerInterceptor {
                 log.warn("xid in change during RPC from {} to {}", rpcXid, unbindXid);
                 if (unbindXid != null) {
                     RootContext.bind(unbindXid);
-                    request.setAttribute(UNBIND_XID, true);
                     log.warn("bind {} back to RootContext", unbindXid);
                 }
             }