Don't get file name when webapp has external provider

Issue:105265

(cherry picked from commit dd4f2a8)

dotnet/src/dotnetframework/GxClasses/Core/GXUtilsCommon.cs

@@ -6070,7 +6070,7 @@ public static string Save(Image bitmap, string imageFile, ImageFormat format)
 				ms.Position = 0;
 				try
 				{
-					if (imageFile.StartsWith("http://") || imageFile.StartsWith("https://"))
+					if ((imageFile.StartsWith("http://") || imageFile.StartsWith("https://")) && ServiceFactory.GetExternalProvider() == null)
 					{
 						Uri uri = new Uri(imageFile);
 						imageFile = Path.GetFileName(uri.AbsolutePath);