[pitivi] previewers: Never pass same target as proxy when finalizing

[Thibault Saunier <tsaunier src gnome org>]

commit 590b00f343e91be2ae9836d30f2321f9b8694986
Author: Thibault Saunier <thibault saunier osg samsung com>
Date:   Thu Feb 9 17:37:23 2017 -0300

    previewers: Never pass same target as proxy when finalizing
    
    Otherwise we might end up symlinking the cache file to itself
    
    Reviewed-by: Alex Băluț <alexandru balut gmail com>
    Differential Revision: https://phabricator.freedesktop.org/D1652

 pitivi/timeline/previewers.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/pitivi/timeline/previewers.py b/pitivi/timeline/previewers.py
index 2396dc0..6113c63 100644
--- a/pitivi/timeline/previewers.py
+++ b/pitivi/timeline/previewers.py
@@ -1042,7 +1042,8 @@ class AudioPreviewer(Previewer, Zoomable, Loggable):
         self._force_redraw = True
 
     def _prepareSamples(self):
-        self._wavebin.finalize(proxy=get_proxy_target(self.ges_elem))
+        proxy = self.ges_elem.get_parent().get_asset().get_proxy_target()
+        self._wavebin.finalize(proxy=proxy)
         self.samples = self._wavebin.samples
 
     def _startRendering(self):