The "Delete" key is ignored by the distances column in the Alignment Editor

Scenario:

1. Open "data/samples/CLUSTALW/COI.aln".
2. Open the "Statistics" options panel tab.
3. Check "Show distances column".
4. Select any row in the distances column.
5. Press the Delete key on the keyboard.
   Expected state: the selected row has been removed.
   Current state: nothing happens.