Add GetSystemInfo to PingController

MarketDataServer/Controllers/PingController.cs

@@ -20,7 +20,7 @@ namespace MarketDataServer.Controllers
     public String GetSystemInfo()
     {
       MDTrace.WriteLine(LogLevel.DEBUG,String.Format("[{0:G}][PingController::GetSystemInfo]", DateTime.Now));
-      return Environment.VersionString.;
+      return Environment.OSVersion.VersionString;
     }    
   }
 }