Enrich the error message more

src/AzzyBot.Bot/Services/Modules/AzuraCastPingService.cs

@@ -19,6 +19,7 @@ public sealed class AzuraCastPingService(ILogger<AzuraCastPingService> logger, A
     private readonly AzuraCastApiService _azuraCast = azuraCast;
     private readonly DbActions _dbActions = dbActions;
     private readonly DiscordBotService _botService = discordBotService;
+    private const string ValidCertNeeded = "The certificate for AzuraCast instance **URI** is self-signed and therefore not valid!\nYou need a valid HTTPS certificate for your AzuraCast instance so AzzyBot can safely connect to it.";
 
     public async Task PingInstanceAsync(AzuraCastEntity azuraCast)
     {
@@ -36,7 +37,7 @@ public async Task PingInstanceAsync(AzuraCastEntity azuraCast)
             if (ex.InnerException is AuthenticationException)
             {
                 _logger.BackgroundServiceInstanceStatus(azuraCast.GuildId, azuraCast.Id, "invalid because of a self-signed certificate");
-                message = $"The certificate for AzuraCast instance **{uri}** is self-signed and therefore not valid!";
+                message = ValidCertNeeded.Replace("**URI**", uri.ToString(), StringComparison.OrdinalIgnoreCase);
             }
             else
             {