Enable running on Windows

Try to setupDirectories using "file:///" protocol when "file://" fails on windows system due to missing authoritative component of the URI.
Don't really know if it can be done in a more elegant way.
The Exception that is raised is : 
Exception in thread "main" java.lang.IllegalArgumentException: URI has an authority component
	at java.io.File.<init>(Unknown Source)
	at de.komoot.photon.importer.elasticsearch.Server.setupDirectories(Server.java:231)
	at de.komoot.photon.importer.elasticsearch.Server.<init>(Server.java:52)
	at de.komoot.photon.importer.App.main(App.java:68)

After two - three minutes of searching with my friends google I find a lot of these kind of solution. As i'm not a Java dev (much more of a C/C++ one) i've posted this fix in order to raise awarness of the existing problem and having an easy way to bypass it.

I don't know if file:/// will work on linux. I didn't try it :/