Revert "Merge pull request #1624 from anthonyhab/fix/slider-opacity-animation"

This reverts commit 4fcd730dd1, reversing
changes made to 0002a6df1c.

Widgets/NColorSlider.qml

@@ -174,6 +174,4 @@ Slider {
       }
     }
   }
-
-  layer.enabled: true
 }

Widgets/NSlider.qml

@@ -141,6 +141,4 @@ Slider {
       }
     }
   }
-
-  layer.enabled: true
 }