Turned all boot messages into clean minetest.log() calls

- Turned all the 'print' calls at server's boot to 'minetest.log' in order to
   render it more clearly

mods/plantlife_modpack/bushes_classic/init.lua

@@ -55,4 +55,4 @@ plantslib:spawn_on_surfaces({
 
 minetest.register_alias("bushes:basket_pies", "bushes:basket_strawberry")
 
-print(S("[Bushes] Loaded."))
+minetest.log("action", S("[Bushes] Loaded."))