Update to pom.xml to fix jsp error markers in STS

When the project is imported into STS from the STS dashboard, the customers.jsp file displays several errors of the form "javax.servlet.jsp.JspException cannot be resolved to a type". These errors don't appear to affect deployment of the project, but have the potential to confuse new users who are looking to use the template to get started with Spring. The proposed change to the pom.xml will resolve the bogus error markers.

STS-3220: customers.jsp displays several errors after importing spring-hibernate-cf project from dashboard
https://issuetracker.springsource.com/browse/STS-3220