Set ed.settingskey to true when returning to editor

This fixes a bug where the settings menu would immediately be brought up
if you used Esc to exit playtesting, unless you were an incredible ninja
and only pressed it for exactly one frame.

desktop_version/src/Game.cpp

@@ -7307,6 +7307,7 @@ void Game::returntoeditor()
     graphics.fademode = 0;
 
     ed.keydelay = 6;
+    ed.settingskey = true;
 
     graphics.backgrounddrawn=false;
     music.fadeout();