war包的启动方式报错，如下：
Failed to execute goal org.apache.maven.plugins:maven-war-plugin:2.2:war (default-war) on project ms-mcms: Error assembling WAR: webxml attribute is required (or pre-existing WEB-INF/web.xml if executing in update mode)
项目中没有web.xml文件，根本就war包的方式部署不了。