Merge pull request #495 from Vocaluxe/FixSubLineAlphaCalculation_release-0.4.1

Fix alpha calculation for last sub line (release-0.4.1)

Vocaluxe/Screens/CScreenSing.cs

@@ -1114,7 +1114,7 @@ namespace Vocaluxe.Screens
                 }
 
                 // sub
-                if (currentLineSub < lines.Length - 2)
+                if ((currentLineSub + 1) < lines.Length)
                 {
                     float diff = CGame.GetTimeFromBeats(lines[currentLineSub + 1].FirstNoteBeat, song.BPM) - currentTime;
 
@@ -1371,4 +1371,4 @@ namespace Vocaluxe.Screens
             }
         }
     }
-}
+}