[pitivi] mediafilespreviewer: Get uri in _handle_new_asset if it is None

[Alexandru Băluț <alexbalut src gnome org>]

commit b6a1384dbeefe228158ad5aaf96fb53f6a7fffa9
Author: Suhas Nayak <suhas2go gmail com>
Date:   Sat Jan 21 15:07:02 2017 +0530

    mediafilespreviewer: Get uri in _handle_new_asset if it is None
    
    Fixes T7674
    
    Reviewed-by: Alex Băluț <alexandru balut gmail com>
    Differential Revision: https://phabricator.freedesktop.org/D1617

 pitivi/mediafilespreviewer.py |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/pitivi/mediafilespreviewer.py b/pitivi/mediafilespreviewer.py
index ab371e0..ab3d982 100644
--- a/pitivi/mediafilespreviewer.py
+++ b/pitivi/mediafilespreviewer.py
@@ -201,6 +201,7 @@ class PreviewWidget(Gtk.Grid, Loggable):
                 asset = GES.UriClipAsset.request_sync(uri)
             else:
                 asset = GES.Asset.request_finish(async_result)
+                uri = asset.get_id()
         except GLib.Error as error:
             self.log("Failed discovering %s: %s", uri, error.message)
             self._show_error(error.message)