Describe the bug

When the Client is run with --showallservers, the Connect Dialog shows all Servers supplied in the Directory server list response, regardless of whether they respond to a "ping" packet. This list now contains a field displayed as "Version".

In this mode, the Client allows sorting the server list by the columns in the dialog, including the Version.

To Reproduce

1. Run the Client with --showallservers in the command line.
2. Open the Connect dialog
3. Select a Directory, e.g. Any Genre 1
4. Make sure the dialog is wide enough to expose the Version column and that the Version column is wide enough to show the versions fully
5. Click the Version column heading to sort by version (ascending). This puts the empty values first (expected).
6. Click the Version column heading a second time to sort by version descending.

Expected behavior

The versions should be in "version sort" order rather than character set sort order.

Version of Jamulus

Jamulus 3.12.0beta2 (or anything after the Version column was introduced)