Fix test on *nix

Author: JunTaoLuo

test/Microsoft.AspNetCore.Http.Tests/Features/FormFeatureTests.cs

@@ -242,7 +242,7 @@ public async Task ReadFormAsync_MultipartWithEncodedFilename_ReturnsParsedFormCo
 
             var file = formCollection.Files["myfile1"];
             Assert.Equal("myfile1", file.Name);
-            Assert.Equal("témp.html", file.FileName);
+            Assert.Equal("t\u00e9mp.html", file.FileName);
             Assert.Equal("text/html", file.ContentType);
             Assert.Equal(@"form-data; name=""myfile1""; filename=""temp.html""; filename*=utf-8''t%c3%a9mp.html", file.ContentDisposition);
             var body = file.OpenReadStream();