fix synthesizing disc tracks with multisession discs when the first session has a large amount of tracks

FirstRecordedTrackNumber only works here for the first session, for future sessions it doesn't work and may just result in out of range exception

src/BizHawk.Emulation.DiscSystem/Internal/Jobs/Synthesize_DiscTracks_From_DiscTOC_Job.cs

@@ -75,8 +75,8 @@ namespace BizHawk.Emulation.DiscSystem
 
 			//fix lead-in track type
 			//guesses:
-			Tracks[0].Control = Tracks[TOCRaw.FirstRecordedTrackNumber].Control;
-			Tracks[0].Mode = Tracks[TOCRaw.FirstRecordedTrackNumber].Mode;
+			Tracks[0].Control = Tracks[1].Control;
+			Tracks[0].Mode = Tracks[1].Mode;
 		}
 	}
 }