update: change default value for backgrounds_updates to false

As discussed on Discord, it's probably what most people want

thcrap_update/src/loader_update.cpp

@@ -651,7 +651,7 @@ BOOL loader_update_with_UI(const char *exe_fn, char *args)
 	state.state = STATE_SELF;
 
 	state.update_at_exit = globalconfig_get_boolean("update_at_exit", false);
-	state.background_updates = globalconfig_get_boolean("background_updates", true);
+	state.background_updates = globalconfig_get_boolean("background_updates", false);
 	state.time_between_updates = (int)globalconfig_get_integer("time_between_updates", 5);
 	state.update_others = globalconfig_get_boolean("update_others", true);