[gnome-documents] edit: fix a runtime warning

[Cosimo Cecchi <cosimoc src gnome org>]

commit f75e55ed34ad77ddc6d2edba5c6050498f8a5799
Author: Cosimo Cecchi <cosimoc gnome org>
Date:   Mon Oct 10 17:53:53 2016 -0700

    edit: fix a runtime warning
    
    Return something from here.

 src/edit.js |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/edit.js b/src/edit.js
index 8a8a2c1..954c37d 100644
--- a/src/edit.js
+++ b/src/edit.js
@@ -149,6 +149,7 @@ const EditToolbar = new Lang.Class({
     },
 
     createSearchbar: function() {
+        return null;
     },
 
     handleEvent: function(event) {