Avoid a malloc(0) (We don't call free on it, valgrind is not happy)

modules/demux/ts.c

@@ -3307,6 +3307,7 @@ static void PMTCallBack( demux_t *p_demux, dvbpsi_pmt_t *p_pmt )
                         break;
                     }
                     pid->es->fmt.i_extra_languages = p_decoded->i_code_count-1;
+                    if( pid->es->fmt.i_extra_languages > 0 )
                         pid->es->fmt.p_extra_languages =
                             malloc( sizeof(*pid->es->fmt.p_extra_languages) *
                                     pid->es->fmt.i_extra_languages );