qml: remove header separtor from KeyNavigableTableView

Signed-off-by: Pierre Lamot <pierre@videolabs.io>

modules/gui/qt/widgets/qml/KeyNavigableTableView.qml

@@ -174,12 +174,6 @@ NavigableFocusScope {
                         }
                     }
                 }
-
-                Rectangle {
-                    width: parent.width
-                    height: 1
-                    color: VLCStyle.colors.textInactive
-                }
             }
         }