[dconf-editor] Disallow toggling if unsensitive.

[Arnaud Bonatti <arnaudb src gnome org>]

commit 0b058955af68c599ca4097c25855f6b48b12af1a
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Dec 11 13:43:26 2017 +0100

    Disallow toggling if unsensitive.
    
    Same problem with info_button, when no search results.

 editor/dconf-window.vala |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/editor/dconf-window.vala b/editor/dconf-window.vala
index c2f9685..27c4a7e 100644
--- a/editor/dconf-window.vala
+++ b/editor/dconf-window.vala
@@ -595,6 +595,8 @@ class DConfWindow : ApplicationWindow
                 if (info_button.active)
                     info_button.active = false;
             }
+            else if (info_button.sensitive == false)
+                return true;
             else if (info_button.active == false)
             {
                 if (bookmarks_button.active)