World start time: Move to first full light (day night ratio = 1000) (#8410)

6125 is the time of first full light according to 'get_node_light()',
and the time of first full light visually when basic shaders are on.
This is the optimum default new world start time, taking all possible
games into account.
The previous time assumed a game similar to Minetest Game. Games
should set this setting themselves according to their needs.

builtin/settingtypes.txt

@@ -1097,7 +1097,7 @@ time_send_interval (Time send interval) int 5
 time_speed (Time speed) int 72
 
 #    Time of day when a new world is started, in millihours (0-23999).
-world_start_time (World start time) int 5250 0 23999
+world_start_time (World start time) int 6125 0 23999
 
 #    Interval of saving important changes in the world, stated in seconds.
 server_map_save_interval (Map save interval) float 5.3

src/defaultsettings.cpp

@@ -355,7 +355,7 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("csm_restriction_noderange", "0");
 	settings->setDefault("max_clearobjects_extra_loaded_blocks", "4096");
 	settings->setDefault("time_speed", "72");
-	settings->setDefault("world_start_time", "5250");
+	settings->setDefault("world_start_time", "6125");
 	settings->setDefault("server_unload_unused_data_timeout", "29");
 	settings->setDefault("max_objects_per_block", "64");
 	settings->setDefault("server_map_save_interval", "5.3");