really remove the python ai stuff (the advanded prefs option this time)

data/_main.cfg

@@ -108,13 +108,6 @@
 #    default=60
 #[/advanced_preference]
 
-[advanced_preference]
-    field=only_run_safe_python_ais
-    name=_"Only Run Safe Python AIs"
-    type=boolean
-    default=yes
-[/advanced_preference]
-
 {game_config.cfg}
 
 [textdomain]

src/game_preferences.cpp

@@ -767,11 +767,6 @@ bool startup_effect()
 	return utils::string_bool(preferences::get("startup_effect"), true);
 }
 
-bool run_safe_python()
-{
-	return utils::string_bool(preferences::get("only_run_safe_python_ais"), true);
-}
-
 std::string get_chat_timestamp(const time_t& t) {
 	if (chat_timestamping()) {
 		return lg::get_timestamp(t, clock_format()) + " ";

src/game_preferences.hpp

@@ -198,8 +198,6 @@ namespace preferences {
 
 	bool startup_effect();
 
-	bool run_safe_python();
-
 	std::set<std::string> &encountered_units();
 	std::set<t_translation::t_terrain> &encountered_terrains();