Startup: add early exit if the home guild doesn't exist

Author: Erisa

Events/ReadyEvent.cs

@@ -6,9 +6,6 @@ public class ReadyEvent
     {
         public static async Task OnReady(DiscordClient client, SessionCreatedEventArgs _)
         {
-
-            homeGuild = await discord.GetGuildAsync(cfgjson.ServerID);
-
             try
             {
                 if (!LogChannelHelper.ready)
@@ -47,6 +44,17 @@ public static async Task OnReady(DiscordClient client, SessionCreatedEventArgs _
 
         public static async Task OnStartup(DiscordClient client)
         {
+            try
+            {
+                homeGuild = await discord.GetGuildAsync(cfgjson.ServerID);
+            }
+            catch
+            {
+                discord.Logger.LogCritical("Error retrieving the home guild using the configured serverID! " +
+                    "Please check that the bot is in the server and that the configuration is correct.");
+                Environment.Exit(1);
+            }
+
             // wait until the log helper is ready
             while (true)
             {