validate:tools:launcher: Take into account the position value when rendering

When rendering a files we try to use the size of the outputed file to
determine wether we are timeout or not, but if that fails
try to check the position

validate/tools/launcher/baseclasses.py

@@ -351,7 +351,11 @@ class GstValidateTest(Test):
     def get_current_size(self):
         position = self.get_current_position()
 
+        try:
             size = os.stat(urlparse.urlparse(self.dest_file).path).st_size
+        except OSError as e:
+            return position
+
         self.debug("Size: %s" % size)
         return size