Remove Lua implementation of wesnoth.units.find_on_recall

Since there's already a native C++ version we might as well just use it.

data/lua/core.lua

@@ -522,20 +522,6 @@ if wesnoth.kernel_type() == "Game Lua Kernel" then
 			end
 		end
 	end
-	
-	function wesnoth.units.find_on_recall(filter)
-		filter = filter or {}
-		if getmetatable(filter) == 'wml object' then
-			filter = filter.__literal
-			filter.x = 'recall'
-			filter.y = 'recall'
-			filter = wml.tovconfig(filter)
-		else
-			filter.x = 'recall'
-			filter.y = 'recall'
-		end
-		return wesnoth.units.find(filter)
-	end
 end
 
 --[========[GUI2 Dialog Manipulations]========]

src/scripting/game_lua_kernel.cpp

@@ -4340,6 +4340,7 @@ game_lua_kernel::game_lua_kernel(game_state & gs, play_controller & pc, reports
 		// Static functions
 		{"create", &intf_create_unit},
 		{"find", &dispatch<&game_lua_kernel::intf_get_units>},
+		{"find_on_recall", &dispatch<&game_lua_kernel::intf_get_recall_units>},
 		{"get", &dispatch<&game_lua_kernel::intf_get_unit>},
 		{ nullptr, nullptr }
 	};