xenapi: removed the default value for xenserver UserAgent

Signed-off-by: Rashmi A Badadale <badadalerashmi@gmail.com>

Author: rashmib-1112

ocaml/sdk-gen/csharp/autogen/src/Session.cs

@@ -48,7 +48,7 @@ public partial class Session : XenObject<Session>
         /// <summary>
         /// This string is used as the HTTP UserAgent for each request.
         /// </summary>
-        public static string UserAgent = $"XenAPI/{Helper.APIVersionString(API_Version.LATEST)}";
+        public static string UserAgent;
 
         /// <summary>
         /// If null, no proxy is used, otherwise this proxy is used for each request.