Styling: do not use thick_lining for selected tool icons.

Affects Per Object Settings and rotate Lay Flat

CURA-6683

resources/themes/cura-light/styles.qml

@@ -240,7 +240,7 @@ QtObject
                     }
                     Behavior on color { ColorAnimation { duration: 50; } }
 
-                    border.width: (control.hasOwnProperty("needBorder") && control.needBorder) ? (control.checked ? Theme.getSize("thick_lining").width : Theme.getSize("default_lining").width) : 0
+                    border.width: (control.hasOwnProperty("needBorder") && control.needBorder) ? Theme.getSize("default_lining").width : 0
                     border.color: control.checked ? Theme.getColor("icon") : Theme.getColor("lining")
                 }
             }