Remove unused menu setslowdown1

Looks like it was a remnant from the Flash days, and the "delete your
saves if you want to use slowdown" was a bit too mean so it stopped
being a thing in the C++ version.

desktop_version/src/Game.cpp

@@ -6753,12 +6753,6 @@ void Game::createmenu( enum Menu::MenuName t )
         menuxoff = -30;
         menuyoff = 64;
         break;
-    case Menu::setslowdown1:
-        option("no, return to options");
-        option("yes, delete saves");
-        menuxoff = -30;
-        menuyoff = 64;
-        break;
     case Menu::setslowdown2:
         option("normal speed");
         option("80% speed");

desktop_version/src/Game.h

@@ -35,7 +35,6 @@ namespace Menu
         controller,
         cleardatamenu,
         setinvincibility,
-        setslowdown1,
         setslowdown2,
         unlockmenu,
         credits,

desktop_version/src/Input.cpp

@@ -392,26 +392,6 @@ void menuactionpress()
             break;
         }
         break;
-    case Menu::setslowdown1:
-        switch (game.currentmenuoption)
-        {
-        case 0:
-            //back
-            music.playef(11);
-            game.createmenu(Menu::accessibility);
-            game.currentmenuoption = 4;
-            map.nexttowercolour();
-            break;
-        case 1:
-            //change game speed
-            game.deletequick();
-            game.deletetele();
-            game.createmenu(Menu::setslowdown2);
-            map.nexttowercolour();
-            music.playef(11);
-            break;
-        }
-        break;
     case Menu::setslowdown2:
         switch (game.currentmenuoption)
         {

desktop_version/src/Render.cpp

@@ -269,12 +269,6 @@ void menurender()
         graphics.Print( -1, 100, "Are you sure you want to ", tr, tg, tb, true);
         graphics.Print( -1, 110, "enable invincibility?", tr, tg, tb, true);
         break;
-    case Menu::setslowdown1:
-        graphics.Print( -1, 90, "Warning! Changing the game speed", tr, tg, tb, true);
-        graphics.Print( -1, 100, "requires a game restart, and will", tr, tg, tb, true);
-        graphics.Print( -1, 110, "delete your current saves.", tr, tg, tb, true);
-        graphics.Print( -1, 120, "Is this ok?", tr, tg, tb, true);
-        break;
     case Menu::setslowdown2:
         graphics.bigprint( -1, 40, "Game Speed", tr, tg, tb, true);
         graphics.Print( -1, 75, "Select a new game speed below.", tr, tg, tb, true);