Lua code: replace deprecated wesnoth.tovconfig() calls

(cherry-picked from commit 138107c)

data/lua/backwards-compatibility.lua

@@ -8,5 +8,5 @@ wesnoth.set_music = wesnoth.deprecate_api('wesnoth.set_music', 'wesnoth.music_li
 -- which also provides "constness" of the passed wml object from the point of view of the caller.
 -- So please don't remove since it's not deprecated.
 function wesnoth.fire(name, cfg)
-	wesnoth.wml_actions[name](wesnoth.tovconfig(cfg or {}))
+	wesnoth.wml_actions[name](wml.tovconfig(cfg or {}))
 end

data/lua/wml-flow.lua

@@ -101,7 +101,7 @@ wesnoth.wml_actions["for"] = function(cfg)
 		loop_lim.last = cfg_lit["end"] or first
 		loop_lim.step = cfg_lit.step or 1
 	end
-	loop_lim = wesnoth.tovconfig(loop_lim)
+	loop_lim = wml.tovconfig(loop_lim)
 	if loop_lim.step == 0 then -- Sanity check
 		helper.wml_error("[for] has a step of 0!")
 	end

data/lua/wml-utils.lua

@@ -127,7 +127,7 @@ function utils.handle_event_commands(cfg, scope_type)
 			elseif string.sub(from, -1) ~= ']' then
 				insert_from = from
 			end
-			arg = wesnoth.tovconfig(arg)
+			arg = wml.tovconfig(arg)
 		end
 		if not string.find(cmd, "^filter") then
 			cmd = wesnoth.wml_actions[cmd] or
@@ -139,7 +139,7 @@ function utils.handle_event_commands(cfg, scope_type)
 					if current_exit ~= "none" then break end
 					j = j + 1
 					if j >= wesnoth.get_variable(insert_from .. ".length") then break end
-					arg = wesnoth.tovconfig(wesnoth.get_variable(string.format("%s[%d]", insert_from, j)))
+					arg = wml.tovconfig(wesnoth.get_variable(string.format("%s[%d]", insert_from, j)))
 				until false
 			else
 				cmd(arg)

data/lua/wml/objectives.lua

@@ -205,7 +205,7 @@ end
 local function maybe_parsed(cfg)
 	if cfg == nil then return nil end
 	if cfg.delayed_variable_substitution == true then
-		return wesnoth.tovconfig(cfg)
+		return wml.tovconfig(cfg)
 	end
 	return cfg
 end