Upgrading plugin tomcat7-maven-plugin and fix error when starting.

- The plugin tomcat7-maven-plugin version 2.1 use Apache Tomcat/7.0.37 and when init throws the Spring exception:
java.lang.IllegalStateException: No suitable default
RequestUpgradeStrategy found. Maybe is missing some dependencies.

- Upgrading to tomcat7-maven-plugin version 2.2 it will use Apache
Tomcat/7.0.47 and run fine without exception.