SAK-25551 Fix failing tests in emailtemplateservice.

The SLF4J version had been bumped in master but the log4j12 implementation haddn't been kept in line. This just gets emailtemplateservice to use the version specified in the dependencyManagement version in master/pom.xml

git-svn-id: https://source.sakaiproject.org/svn/emailtemplateservice/trunk@133377 66ffb92e-73f9-0310-93c1-f5514f145a0a