[LMS-2336] hide 'delete permanently' button

SVN: 22209

openbis/source/java/ch/systemsx/cisd/openbis/generic/client/web/client/application/ui/deletion/DeletionGrid.java

@@ -126,7 +126,7 @@ public class DeletionGrid extends TypedTableGrid<Deletion>
                                             deletions, createRefreshCallback(invoker));
                                 }
                             });
-        // TODO unsafe
+        deletePermanentlyButton.hide(); // FIXME rollback of deleted data sets is not possible
         addButton(deletePermanentlyButton);
         allowMultipleSelection(); // we allow deletion/revert of multiple deletions