[gnome-calendar] css: fix a bogus selector from the previous commit.

[Lapo Calamandrei <lapo src gnome org>]

commit 7160da43a7ee54bfc804725b63cd346c827e20c2
Author: Lapo Calamandrei <calamandrei gmail com>
Date:   Fri Jul 8 01:28:16 2016 +0200

    css: fix a bogus selector from the previous commit.

 data/theme/gtk-styles.css |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/theme/gtk-styles.css b/data/theme/gtk-styles.css
index 14274ec..5e583fc 100644
--- a/data/theme/gtk-styles.css
+++ b/data/theme/gtk-styles.css
@@ -175,7 +175,7 @@ calendar-view.second-view-header {
 }
 
 /* no events label */
-.year-view box.sidebar:nth-child(2) {
+.year-view box.sidebar label:nth-child(2) {
     margin-top: 4px;
 }