Fix music playing when crepitus is present (#341)

UseCreatureMusic( HostileZombiesPresent() ); was overriding the music mode set in PrepareCreaturesForBattle() when encountering crepitus or being in the creature caves, resulting in regular tense and battle music being played.

Strategic/Meanwhile.cpp

@@ -864,7 +864,7 @@ void EndMeanwhile( )
 	{
 		// We leave this sector open for our POWs to escape!
 		// Set music mode to enemy present!
-		UseCreatureMusic(HostileZombiesPresent());
+		CheckForZombieMusic();
 
 		SetMusicMode( MUSIC_TACTICAL_ENEMYPRESENT );