[epiphany] prefs-dialog: Give the background style to the pages

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d320ad701e34821a4cbe5b34b857e793bca86023
Author: Adrien Plazas <kekun plazas laposte net>
Date:   Tue Jun 25 12:41:55 2019 +0200

    prefs-dialog: Give the background style to the pages
    
    This avoids to make the rows white on a white background and make the
    actual preferences easier to see.

 src/resources/gtk/prefs-dialog.ui | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
---
diff --git a/src/resources/gtk/prefs-dialog.ui b/src/resources/gtk/prefs-dialog.ui
index 0d83f0d9a..61a03463b 100644
--- a/src/resources/gtk/prefs-dialog.ui
+++ b/src/resources/gtk/prefs-dialog.ui
@@ -32,6 +32,9 @@
                 <property name="icon_name">applications-system-symbolic</property>
                 <property name="title" translatable="yes">General</property>
                 <property name="visible">True</property>
+                <style>
+                  <class name="background"/>
+                </style>
                 <child>
                   <object class="HdyPreferencesGroup">
                     <property name="title" translatable="yes">Browsing</property>
@@ -392,6 +395,9 @@
                 <property name="icon_name">document-edit-symbolic</property>
                 <property name="title" translatable="yes">Fonts &amp; Style</property>
                 <property name="visible">True</property>
+                <style>
+                  <class name="background"/>
+                </style>
                 <child>
                   <object class="HdyPreferencesGroup">
                     <property name="title" translatable="yes">Fonts</property>
@@ -567,6 +573,9 @@
                 <property name="icon_name">drive-harddisk-symbolic</property>
                 <property name="title" translatable="yes">Stored Data</property>
                 <property name="visible">True</property>
+                <style>
+                  <class name="background"/>
+                </style>
                 <child>
                   <object class="HdyPreferencesGroup">
                     <property name="title" translatable="yes">Cookies</property>
@@ -736,6 +745,9 @@
                 <property name="icon_name">emoji-flags-symbolic</property>
                 <property name="title" translatable="yes">Language</property>
                 <property name="visible">True</property>
+                <style>
+                  <class name="background"/>
+                </style>
                 <child>
                   <object class="HdyPreferencesGroup">
                     <property name="title" translatable="yes">Languages</property>
@@ -930,6 +942,9 @@
                 <property name="icon_name">emblem-synchronizing-symbolic</property>
                 <property name="title" translatable="yes">Sync</property>
                 <property name="visible">True</property>
+                <style>
+                  <class name="background"/>
+                </style>
                 <child>
                   <object class="HdyPreferencesGroup" id="sync_page_box">
                     <property name="description" translatable="yes">Sign in with your Firefox account to 
sync your data with Web and Firefox on other computers. Web is not Firefox and is not produced or endorsed by 
Mozilla.</property>