Ensure that handler property of classpath URLs is not lost.

We use a custom classloader for bundled jars (EmJar, https://github.com/comoyo/commons/tree/master/emjar-maven-plugin). The 0.9.9 release of Reflections breaks classpath scanning in this scenario.  Passing the classpath elements through `distinctUrls` converts them from `URL` to `URI` and back again, causing the `handler` property to be lost. Thus the subsequent calls to `url.openConnection()` fall back to `JarURLConnection` instead of the custom nesting-aware implementation that was represented by the original `handler`. This patch ensures that the original `URL` objects are used.