librem5: Drop the custom .needs-attention style class

This conflicts with the one from the view switcher.

src/gtk-style-hc.css

@@ -22,12 +22,6 @@
 	font-size: 125%;
 }
 
-.needs-attention {
-	background-image: none;
-	background-color: shade(@theme_selected_bg_color, 1.1);
-	border-radius: 1px;
-}
-
 .screenshot-image, .screenshot-image-thumb {
 	background-image: none;
 	background-color: shade(@theme_bg_color, 0.9);

src/gtk-style.css

@@ -38,12 +38,6 @@
 	font-size: x-small;
 }
 
-.needs-attention {
-	background-image: none;
-	background-color: shade(@theme_selected_bg_color, 1.1);
-	border-radius: 1px;
-}
-
 .toolbar-primary-buttons-software {
 	padding-left: 26px;
 	padding-right: 26px;