textproc/kdiff3: update to 1.8.5

Version 1.8.5 - 2020-01-10

BUG:417189 Fix url handling for drag and drop.
BUG:426823 Fix regression in handing paste from clipboard to blank diff window.
*Fix link detection via KIO
*Drop custom event filter in OpenDialog. We now use FileNameLineEdit instead as in the main window.
*Fix url/path handling bugs for remote files
*Don't ignore stat errors unless it tells us the file was not found.