#182 Revert workaround for HttpResponseMessage.ReasonPhrase.

Author: Tratcher

test/Microsoft.AspNetCore.Server.WebListener.FunctionalTests/ResponseTests.cs

@@ -97,7 +97,7 @@ public async Task Response_ServerSendsCustomStatus_NoReasonPhrase()
             {
                 HttpResponseMessage response = await SendRequestAsync(address);
                 Assert.Equal(901, (int)response.StatusCode);
-                Assert.True(string.IsNullOrEmpty(response.ReasonPhrase)); // https://github.com/dotnet/corefx/issues/6721
+                Assert.Equal(string.Empty, response.ReasonPhrase);
                 Assert.Equal(string.Empty, await response.Content.ReadAsStringAsync());
             }
         }

test/Microsoft.Net.Http.Server.FunctionalTests/ResponseTests.cs

@@ -87,7 +87,7 @@ public async Task Response_ServerSendsCustomStatus_NoReasonPhrase()
 
                 HttpResponseMessage response = await responseTask;
                 Assert.Equal(901, (int)response.StatusCode);
-                Assert.True(string.IsNullOrEmpty(response.ReasonPhrase)); // https://github.com/dotnet/corefx/issues/6721
+                Assert.Equal(string.Empty, response.ReasonPhrase);
                 Assert.Equal(string.Empty, await response.Content.ReadAsStringAsync());
             }
         }