[IMP] web: darker highlight selection

addons/web/static/lib/bootstrap/less/variables.less

@@ -245,7 +245,7 @@
 //** Hover color for dropdown links.
 @dropdown-link-hover-color:      darken(@gray-dark, 5%);
 //** Hover background for dropdown links.
-@dropdown-link-hover-bg:         #f5f5f5;
+@dropdown-link-hover-bg:         #d1d1d1;
 
 //** Active dropdown menu item text color.
 @dropdown-link-active-color:     @component-active-color;