[pclasses & mff_pclasses] Use implicit on_update

- After executing on_unassigned and on_assigned, implicitly call
   on_update (or add a dummy on_update for assigning if there is none)

mods/mff/mff_pclasses/admin.lua

@@ -11,12 +11,9 @@ pclasses.api.register_class("admin", {
 		if inform then
 			minetest.chat_send_player(pname, "Hello admin.")
 		end
-		pclasses.api.util.on_update(pname)
 	end,
 	on_unassigned = function(pname)
 	end,
-	on_update = function(pname)
-	end,
 	switch_params = {
 		color = {r = 255, g = 00, b = 224},
 		holo_item = "maptools:pick_admin"

mods/mff/mff_pclasses/hunter.lua

@@ -12,7 +12,6 @@ pclasses.api.register_class("hunter", {
 			minetest.chat_send_player(pname, "You are now a hunter")
 			minetest.sound_play("pclasses_full_hunter", {to_player=pname, gain=1})
 		end
-		pclasses.api.util.on_update(pname)
 		minetest.log("action", "[PClasses] Player " .. pname .. " become a hunter")
 	end,
 	on_unassigned = function(pname)

mods/mff/mff_pclasses/warrior.lua

@@ -12,7 +12,6 @@ pclasses.api.register_class("warrior", {
 			minetest.sound_play("pclasses_full_warrior", {to_player=pname, gain=1})
 			minetest.chat_send_player(pname, "You are now a warrior")
 		end
-		pclasses.api.util.on_update(pname)
 		minetest.log("action", "[PClasses] Player " .. pname .. " becomes a warrior")
 	end,
 	on_unassigned = function(pname)

mods/mff/mff_pclasses/wizard.lua

@@ -13,7 +13,6 @@ pclasses.api.register_class("wizard", {
 			minetest.chat_send_player(pname, "You are now a wizard.")
 		end
 		-- Add specs here
-		pclasses.api.util.on_update(pname)
 		minetest.log("action", "[PClasses] Player " .. pname .. " becomes a wizard")
 	end,
 	on_unassigned = function(pname)