Fix duplicate jar name when artifact classifier is used

We ran into a problem where our packaged app's classpath was being generated incorrectly. We have two artifacts with the same coordinates, except one has a classifier. In this case the scriptClasspath ended up having two entries with the same name, but only one ended up in the lib directory (in our case it was the wrong one).

This patch adds the classifier to the jar name if one exists so that all files are packaged.