When you set "clean install" on your root pom. Then Jenkins will try to start a seperate instance of tomcat on your server on the same port. 

The Jenkins error doesn' t give the right info:
Caused by: java.net.SocketException: Connection reset

That's not the real issue. On the server it gives:
java.net.BindException: Address already in use (Bind failed)

Jenkins shouldnt be trying to start another instance. Nowhere did I tell Jenkins to be creating other instances. I'm only deploying to 1 tomcat server. 

This is a blocking defect. Can't use Jenkins with Tomcat anymore.