MQTTnet.Server: Fix version detection.

Source/MQTTnet.Server/Controllers/ServerController.cs

@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
+using System.Diagnostics;
 using System.Reflection;
 
 namespace MQTTnet.Server.Controllers
@@ -12,7 +13,8 @@ namespace MQTTnet.Server.Controllers
         [HttpGet]
         public ActionResult<string> GetVersion()
         {
-            return Assembly.GetExecutingAssembly().GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion;
+            var fileVersion = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location);
+            return fileVersion.ProductVersion.ToString();
         }
     }
 }

Source/MQTTnet.Server/MQTTnet.Server.csproj

@@ -19,7 +19,7 @@
   </PropertyGroup>
 
   <PropertyGroup>
-    <StartupObject></StartupObject>
+    <StartupObject>MQTTnet.Server.Program</StartupObject>
     <UserSecretsId>c564f0de-28b4-45bf-b726-4d665d705653</UserSecretsId>
   </PropertyGroup>
 

Source/MQTTnet.Server/Program.cs

@@ -2,6 +2,7 @@
 using Microsoft.Extensions.Hosting;
 using MQTTnet.Server.Web;
 using System;
+using System.Diagnostics;
 using System.Reflection;
 
 namespace MQTTnet.Server
@@ -58,8 +59,11 @@ namespace MQTTnet.Server
             Console.WriteLine(@"https://github.com/chkr1011/MQTTnet");
 
             Console.ForegroundColor = ConsoleColor.White;
+
+            var fileVersion = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location);
+
             Console.WriteLine($@"
-Version:    {Assembly.GetExecutingAssembly().GetCustomAttribute<AssemblyInformationalVersionAttribute>().InformationalVersion}
+Version:    {fileVersion.ProductVersion}
 License:    MIT (read LICENSE file)
 Sponsoring: https://opencollective.com/mqttnet
 Support:    https://github.com/chkr1011/MQTTnet/issues