CMIS-436: fixed basic auth

git-svn-id: https://svn.apache.org/repos/asf/chemistry/dotcmis/trunk@1180029 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/DotCMIS/binding/binding-intf.cs b/DotCMIS/binding/binding-intf.cs
index 3819fc9..fc27ce9 100644
--- a/DotCMIS/binding/binding-intf.cs
+++ b/DotCMIS/binding/binding-intf.cs
@@ -91,7 +91,10 @@
             {

                 if (user != null || password != null)

                 {

-                    request.Credentials = new NetworkCredential(user ?? "", password ?? "");

+                    if (request.Headers.GetValues("Authorization") == null)

+                    {

+                        request.Headers.Add("Authorization", "Basic " + Convert.ToBase64String(System.Text.Encoding.ASCII.GetBytes((user ?? "") + ":" + (password ?? ""))));

+                    }

                 }

                 return;

             }