[epiphany] Fix overview thumbnails not appearing after Ctrl+T

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 08fbe8cdc229d1d504079fdbeaa521f39833b4dc
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Tue May 22 20:10:14 2018 -0500

    Fix overview thumbnails not appearing after Ctrl+T
    
    OverviewItem.thumbnailPath always returns null because the double quote
    characters are missing. Fix it.

 embed/web-extension/resources/js/overview.js |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/embed/web-extension/resources/js/overview.js b/embed/web-extension/resources/js/overview.js
index ced2ee6..7e5fccd 100644
--- a/embed/web-extension/resources/js/overview.js
+++ b/embed/web-extension/resources/js/overview.js
@@ -204,8 +204,8 @@ Ephy.Overview.Item = class OverviewItem
         if (!background)
             return null;
 
-        if (background.startsWith('url(file://'))
-            return background.replace('url(file://', '').replace(') no-repeat', '');
+        if (background.startsWith('url("file://'))
+            return background.replace('url("file://', '').replace('") no-repeat', '');
 
         return null;
     }