fixed style issues

Author: chengyouling

clients/config-center-client/src/main/java/org/apache/servicecomb/config/center/client/ConfigCenterAddressManager.java

@@ -17,7 +17,6 @@
 
 package org.apache.servicecomb.config.center.client;
 
-import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.servicecomb.http.client.common.AbstractAddressManager;

demo/demo-multi-service-center/demo-multi-service-center-client/src/main/java/org/apache/servicecomb/demo/multiServiceCenterClient/RegistryClientTest.java

@@ -70,7 +70,7 @@ public RegistryClientTest(Environment environment) {
   @Override
   public void testRestTransport() throws Exception {
     ServiceCenterAddressManager addressManager = new ServiceCenterAddressManager("default",
-        Arrays.asList("http://127.0.0.1:30100"),new ArrayList<>(), new ArrayList<>(), new EventBus());
+        Arrays.asList("http://127.0.0.1:30100"), new ArrayList<>(), new ArrayList<>(), new EventBus());
     SSLProperties sslProperties = new SSLProperties();
     sslProperties.setEnabled(false);
     ServiceCenterClient serviceCenterClient = new ServiceCenterClient(addressManager, sslProperties,

demo/docker-build-config/pom.xml

@@ -42,7 +42,7 @@
                 <name>${project.artifactId}:${project.version}</name>
                 <alias>${project.artifactId}</alias>
                 <build>
-                  <from>openjdk:8-jre-alpine</from>
+                  <from>openjdk8</from>
                   <ports>
                     <port>7070</port>
                     <port>8080</port>

service-registry/registry-service-center/src/main/java/org/apache/servicecomb/serviceregistry/refresh/ServiceRegistryAddressManager.java

@@ -18,7 +18,6 @@
 package org.apache.servicecomb.serviceregistry.refresh;
 
 import java.net.URI;
-import java.util.ArrayList;
 import java.util.List;
 
 import org.apache.servicecomb.foundation.common.net.IpPort;