mpdparser: Don't set variable just to overwrite it again later

We set it to TRUE here, but later we set it to TRUE again anyway if the
parsing actually succeeded at this point. Let's keep the second one.

CID 1374360.

ext/dash/gstmpdparser.c

@@ -1630,7 +1630,6 @@ gst_mpdparser_parse_mult_seg_base_type_ext (GstMultSegmentBaseType ** pointer,
         /* parse frees the segmenttimeline if any */
         gst_mpdparser_parse_segment_timeline_node
             (&mult_seg_base_type->SegmentTimeline, cur_node);
-        has_timeline = TRUE;
       } else if (xmlStrcmp (cur_node->name,
               (xmlChar *) "BitstreamSwitching") == 0) {
         /* parse frees the old url before setting the new one */