Adwaita: Insensitive labels

There is an insensitive label in widget-factory which was
not getting any different from the sensitive label next
to it. With this patch, it does, again.

gtk/resources/theme/Adwaita/_common.scss

@@ -138,6 +138,9 @@ GtkLabel {
   &:backdrop:selected {
     @extend %selected_items;
   }
+  &:insensitive {
+    color: $insensitive_fg_color;
+  }
 }
 
 .dim-label {

gtk/resources/theme/Adwaita/gtk-contained-dark.css

@@ -116,6 +116,9 @@
 .overshoot {
   background-color: rgba(33, 93, 156, 0.2); }
 
+GtkLabel:insensitive {
+  color: #939695; }
+
 .dim-label, .titlebar .subtitle, GtkCalendar.header .subtitle,
 .header-bar .subtitle {
   opacity: 0.55;

gtk/resources/theme/Adwaita/gtk-contained.css

@@ -116,6 +116,9 @@
 .overshoot {
   background-color: rgba(74, 144, 217, 0.2); }
 
+GtkLabel:insensitive {
+  color: #8d9091; }
+
 .dim-label, .titlebar .subtitle, GtkCalendar.header .subtitle,
 .header-bar .subtitle {
   opacity: 0.55;