Add inspecial() checks to savetele() and savequick()

This prevents the game from being saved if you manage to trigger a
savetele() during a "special" gamemode (like if you use the Gravitron
out-of-bounds glitch when replaying Intermission 2, then go to Game
Complete that way).

desktop_version/src/Game.cpp

@@ -5916,7 +5916,7 @@ void Game::savetele()
 {
     //TODO make this code a bit cleaner.
 
-    if (map.custommode)
+    if (map.custommode || inspecial())
     {
         //Don't trash save data!
         return;
@@ -6112,7 +6112,7 @@ void Game::savetele()
 
 void Game::savequick()
 {
-    if (map.custommode)
+    if (map.custommode || inspecial())
     {
         //Don't trash save data!
         return;