Implemented match group instead of tinkering with the URL string

We're using regex already anyways, so might as well take advantage of matching groups. Group 1 will always be the country code and group 2 always the ID

LightlessSyncServer/LightlessSyncServices/Discord/MareWizardModule.cs

@@ -329,13 +329,12 @@ public partial class LightlessWizardModule : InteractionModuleBase
 
     private int? ParseCharacterIdFromLodestoneUrl(string lodestoneUrl)
     {
-        var regex = new Regex(@"https:\/\/(na|eu|de|fr|jp)\.finalfantasyxiv\.com\/lodestone\/character\/\d+");
+        var regex = new Regex(@"^https:\/\/(na|eu|de|fr|jp)\.finalfantasyxiv\.com\/lodestone\/character\/(\d{8})/?$");
         var matches = regex.Match(lodestoneUrl);
         var isLodestoneUrl = matches.Success;
         if (!isLodestoneUrl || matches.Groups.Count < 1) return null;
+        var stringId = matches.Groups[2].ToString();
 
-        lodestoneUrl = matches.Groups[0].ToString();
-        var stringId = lodestoneUrl.Split('/', StringSplitOptions.RemoveEmptyEntries).Last();
         if (!int.TryParse(stringId, out int lodestoneId))
         {
             return null;