Rename base timespeed setting

All setting names we use that aren't base
settings should be prefixed with modname.

szutil_clocksync/init.lua

@@ -5,7 +5,9 @@ local math_floor, math_random, os_date
     = math.floor, math.random, os.date
 -- LUALOCALS > ---------------------------------------------------------
 
-local basespeed = tonumber(minetest.settings:get("time_speed_base")) or 72
+local modname = minetest.get_current_modname()
+local basespeed = tonumber(minetest.settings:get(modname
+		.. "_time_speed_base")) or 72
 
 local dt, mt, rt, diff, ts
 local expire = 0