Revert part of "Fix music stopping when restarting time trial"

This reverts only a part of f196fcd896 -
as the original commit author did not do their changes atomically, they
also squashed in a de-duplication within the same commit. So I'm only
reverting the part of the commit that wasn't the de-duplication, which
is simply the changes to the music.fadeout() calls.

This is being (partially) reverted for several reasons:

1. It's not the correct behavior. What this does instead is persist the
   track through after you restart the time trial, instead of fading it
   out, then restarting it again. This is in contrast to behavior in
   2.2, and I see no reason to not keep the same behavior.

2. It's a single-case patch. The time trials are not the only time in
   the game a music track could fade out and then be restarted with the
   same track - custom levels could do the same thing too. Instead of
   fixing only one case, we should strive to fix EVERY case.

The original commit author (trelbutate) also didn't write anything in
the commit description of f196fcd896. What
you should write in the commit description is things like rationale,
analysis, and other good information that would be useful to anyone
looking at your commit to understand why you did what you did. Having no
commit description leaves readers in the dark as to why you did what you
did.

Thus, I don't know why trelbutate went with this solution, or if they
knew that it was only a single-case patching, or if they knew that it
wasn't 2.2 behavior.

By not writing the commit description, they miss a chance for
reflection; speaking from personal experience, I myself have gone back
and improved my commits countless times because I wrote commit
descriptions for every single one of them, and sometimes whenever I
write them, I think to myself "hang on a minute, that doesn't sound
quite right" and end up finding improvements.

If trelbutate wrote a commit description, they might have realized that
it wasn't 2.2 behavior, and gone back and fixed up their commit to be
correct. As it stands, though, they didn't have to think about it in the
first place because they never bothered to write a commit description.

desktop_version/src/Input.cpp

@@ -2095,6 +2095,7 @@ void gameinput(void)
         //Quick restart of time trial
         graphics.fademode = 2;
         game.completestop = true;
+        music.fadeout();
         game.quickrestartkludge = true;
     }
     else if (game.intimetrial)

desktop_version/src/Script.cpp

@@ -2719,8 +2719,7 @@ void scriptclass::startgamemode( int t )
 	case 7:
 	case 8:
 		//Start Time Trial
-		if (!game.intimetrial)
-			music.fadeout();
+		music.fadeout();
 
 		hardreset();
 		game.nocutscenes = true;