Fix race condition on exit to menu

src/game.cpp

@@ -1018,10 +1018,10 @@ static void show_pause_menu(FormspecFormSource* current_formspec,
 
 	std::string formspec =
 		"size[11,5.5,true]"
-		"button_exit[4,1;3,0.5;btn_continue;"  + std::string(gettext("Continue"))+ "]"
-		"button[4,2;3,0.5;btn_sound;"     + std::string(gettext("Sound Volume")) + "]"
-		"button[4,3;3,0.5;btn_exit_menu;" + std::string(gettext("Exit to Menu")) + "]"
-		"button[4,4;3,0.5;btn_exit_os;"   + std::string(gettext("Exit to OS"))   + "]"
+		"button_exit[4,1;3,0.5;btn_continue;"  + std::string(gettext("Continue"))     + "]"
+		"button_exit[4,2;3,0.5;btn_sound;"     + std::string(gettext("Sound Volume")) + "]"
+		"button_exit[4,3;3,0.5;btn_exit_menu;" + std::string(gettext("Exit to Menu")) + "]"
+		"button_exit[4,4;3,0.5;btn_exit_os;"   + std::string(gettext("Exit to OS"))   + "]"
 		"textarea[7.5,0.25;3.75,6;;" + std::string(control_text) + ";]"
 		"textarea[0.4,0.25;3.5,6;;" + os.str() + ";]"
 		;