With dubbo-samples-rest , see "No Spring WebApplicationInitializer types detected on classpath" when run tomcat

**Put dubbo-samples-rest-1.0-SNAPSHOT.war to ROOT.war to tomcat and run *startup.bat*, see this issue:**

23-Jun-2019 15:42:49.808 信息 [localhost-startStop-1] org.apache.catalina.core.ApplicationContext.log No Spring WebApplicationInitializer types detected on classpath
23-Jun-2019 15:42:50.068 严重 [localhost-startStop-1] org.apache.catalina.core.StandardContext.listenerStart Error configuring application listener of class [com.alibaba.dubbo.remoting.http.servlet.BootstrapListener]
java.lang.ClassNotFoundException: com.alibaba.dubbo.remoting.http.servlet.BootstrapListener
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1364)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1185)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:546)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:527)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:150)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4692)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5236)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:754)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:744)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:980)
at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1851)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
23-Jun-2019 15:42:50.124 严重 [localhost-startStop-1] org.apache.catalina.core.StandardContext.listenerStart Skipped installing application listeners due to previous error(s)
23-Jun-2019 15:42:51.364 信息 [localhost-startStop-1] org.apache.catalina.core.ApplicationContext.log ContextListener: contextInitialized()