[gnome-calendar] css: remove some ugly selectors

[Lapo Calamandrei <lapo src gnome org>]

commit 8be2ece30e50c706dc9578e5038301b197ec088d
Author: Lapo Calamandrei <calamandrei gmail com>
Date:   Fri Jul 8 21:53:08 2016 +0200

    css: remove some ugly selectors
    
    since Georges added all the styleclasses in the needed places.

 data/theme/gtk-styles.css |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/data/theme/gtk-styles.css b/data/theme/gtk-styles.css
index a514f7a..592bb0e 100644
--- a/data/theme/gtk-styles.css
+++ b/data/theme/gtk-styles.css
@@ -300,10 +300,8 @@ event-widget.color-light:backdrop {
 /* adds a subtle shadow to the calendar color dot when it makes sense */
 button:active:not(:backdrop) .calendar-color-image,
 button:checked:not(:backdrop) .calendar-color-image,
-.calendars-list modelbutton image:dir(ltr):first-child:not(:backdrop):not(:disabled),
-.calendars-list modelbutton image:dir(ltr):last-child:not(:backdrop):not(:disabled),
-.calendars-list row image:dir(ltr):first-child:not(:backdrop):not(:disabled),
-.calendars-list row image:dir(ltr):last-child:not(:backdrop):not(:disabled),
+.calendars-list .calendar-color-image:not(:backdrop):not(:disabled),
+.calendar-list .calendar-color-image:not(:backdrop):not(:disabled),
 .sources-button:not(:backdrop):not(:disabled) .calendar-color-image {
     -gtk-icon-shadow: 0 1px alpha(black, 0.1);
 }