removed little blue stripe when mouse over grouped window list icon

cinnamon/cinnamon.css

@@ -545,14 +545,6 @@ StScrollBar StButton#vhandle:active, StScrollBar StButton#hhandle:active { backg
 
 .grouped-window-list-item-box:hover, .window-list-item-box:hover { background-color: rgba(17, 17, 17, 0.12); color: black; }
 
-.panel-top .grouped-window-list-item-box:hover, .panel-top .window-list-item-box:hover { box-shadow: inset 0 -2px rgba(41, 51, 240, 1); }
-
-.panel-bottom .grouped-window-list-item-box:hover, .panel-bottom .window-list-item-box:hover { box-shadow: inset 0 -2px rgba(41, 51, 240, 1); }
-
-.panel-left .grouped-window-list-item-box:hover, .panel-left .window-list-item-box:hover { box-shadow: inset 2px 0 rgba(41, 51, 240, 1); }
-
-.panel-right .grouped-window-list-item-box:hover, .panel-right .window-list-item-box:hover { box-shadow: inset -2px 0 rgba(41, 51, 240, 1); }
-
 .grouped-window-list-item-box:active:focus, .grouped-window-list-item-box:checked:focus, .window-list-item-box:active, .window-list-item-box:checked, .window-list-item-box:focus, .window-list-item-box:running { background-color: rgba(54, 154, 255, 0.50); color: black; }
 
 .panel-top .grouped-window-list-item-box:active:focus, .panel-top .grouped-window-list-item-box:checked:focus, .panel-top .window-list-item-box:active, .panel-top .window-list-item-box:checked, .panel-top .window-list-item-box:focus, .panel-top .window-list-item-box:running { box-shadow: inset 0 -2px #3f51b5; }