dash: Parser: Ignore segments without sourceURL

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
(cherry picked from commit fd878713)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/stream_filter/dash/mpd/BasicCMParser.cpp

@@ -335,6 +335,7 @@ bool    BasicCMParser::setSegments          (Node *root, SegmentInfo *info)
     {
         Segment *seg = new Segment();
         parseSegment( seg, segments.at(i)->getAttributes() );
+        if ( seg->getSourceUrl().empty() == false )
             info->addSegment(seg);
     }
     return true;