[epiphany] GSettings: Explain "disable-history" key

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 86d156f74e51f365e62e4e5e581a9b8ba1e4e92e
Author: Christian Stadelmann <dev genodeftest de>
Date:   Mon Apr 24 15:36:55 2017 +0200

    GSettings: Explain "disable-history" key
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768600

 data/org.gnome.epiphany.gschema.xml |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/data/org.gnome.epiphany.gschema.xml b/data/org.gnome.epiphany.gschema.xml
index f1f3d27..bb882eb 100644
--- a/data/org.gnome.epiphany.gschema.xml
+++ b/data/org.gnome.epiphany.gschema.xml
@@ -269,6 +269,8 @@
                </key>
                <key type="b" name="disable-history">
                        <default>false</default>
+                       <summary>Disable forward and back buttons</summary>
+                       <description>If set to “true”, forward and back buttons are disabled, preventing 
users from accessing immediate browser history</description>
                </key>
                <key type="b" name="disable-save-to-disk">
                        <default>false</default>