#234 RC3: Change language dialog doesn't provide CANCEL button

[Michael Tucker]

The localised text displayed in the dialog to confirm a
change in UI language states:

Title: Message
Text: To localize all controls of iPodder a restart is
required. Click Ok to shutdown cleanly, cancel to
continue.

Expected:

OK and Cancel buttons on the dialog.

Observed:

There is no cancel button, and dismissing the dialog
using the close icon in the title bar restarts iPodder.