Changed the port used when performing auth with YouTube to be random …

…instead of fixed (issue #32)

src/main/java/io/github/stekeblad/videouploader/youtube/Auth.java

@@ -48,8 +48,7 @@ public static Credential authUser() throws IOException {
                 HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, scope).setDataStoreFactory(fileFactory)
                 .build();
 
-        LocalServerReceiver localReceiver = new LocalServerReceiver.Builder().setPort(7835).build();
-        return new AuthorizationCodeInstalledApp(authFlow, localReceiver).authorize("user");
+        return new AuthorizationCodeInstalledApp(authFlow, new LocalServerReceiver()).authorize("user");
     }
 
     /**