[gnome-software] Fix in-app notification close button alignment

[Kalev Lember <klember src gnome org>]

commit 6ec7198ea93874537c553271719f062fcd1bc0e0
Author: Kalev Lember <klember redhat com>
Date:   Thu Mar 8 13:46:06 2018 +0100

    Fix in-app notification close button alignment
    
    Align it to the top, so that it doesn't look out of place for multi-line
    notifications.
    
    Thanks to Andreas Nilsson for noticing!

 src/gnome-software.ui | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/gnome-software.ui b/src/gnome-software.ui
index 91f3fadf..33c8bb4d 100644
--- a/src/gnome-software.ui
+++ b/src/gnome-software.ui
@@ -409,7 +409,7 @@
                     <child>
                       <object class="GtkButton" id="button_events_dismiss">
                         <property name="visible">True</property>
-                        <property name="valign">GTK_ALIGN_CENTER</property>
+                        <property name="valign">start</property>
                         <style>
                           <class name="flat"/>
                         </style>