Re-add some code that was removed during TFM churn

src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

@@ -207,7 +207,7 @@ namespace Microsoft.AspNetCore.Hosting.Internal
 
                 var model = new ErrorPageModel
                 {
-                    RuntimeDisplayName = ".NET Core"
+                    RuntimeDisplayName = RuntimeInformation.FrameworkDescription
                 };
                 var systemRuntimeAssembly = typeof(System.ComponentModel.DefaultValueAttribute).GetTypeInfo().Assembly;
                 var assemblyVersion = new AssemblyName(systemRuntimeAssembly.FullName).Version.ToString();

src/Microsoft.AspNetCore.Server.IntegrationTesting/Common/RetryHelper.cs

@@ -56,7 +56,7 @@ namespace Microsoft.AspNetCore.Server.IntegrationTesting
                     }
                     else
                     {
-                        if (exception is HttpRequestException)
+                        if (exception is HttpRequestException || exception is WebException)
                         {
                             logger.LogWarning("Failed to complete the request : {0}.", exception.Message);
                             await Task.Delay(1 * 1000); //Wait for a while before retry.