Remove unnecessary currentmenuoption reassignments

Now that recreating the same menu keeps currentmenuoption, we can remove
all these superfluous assignments. This means repeating ourselves less;
in case the option numbers change in the future, we won't have to
remember to update these reassignments, too.

desktop_version/src/Game.cpp

@@ -6196,13 +6196,7 @@ void Game::returntomenu(enum Menu::MenuName t)
 {
     if (currentmenuname == t)
     {
-        //Re-create the menu
-        int keep_menu_option = currentmenuoption;
         createmenu(t, true);
-        if (keep_menu_option < (int) menuoptions.size())
-        {
-            currentmenuoption = keep_menu_option;
-        }
         return;
     }