Fixing diagnostics image for 1.1 (#5018)

Diagnostics image 1.1 currently fails for WebSockets when we add a proxy. But 1.2 works for this case. I copy pasted from 1.2 code to 1.1, since we were doing it in a different way in 1.2. I tested it with a proxy, and it works.

edge-modules/iotedge-diagnostics-dotnet/src/Program.cs

@@ -7,6 +7,7 @@ namespace Diagnostics
     using System.Net;
     using System.Net.Http;
     using System.Net.Sockets;
+    using System.Security.Authentication;
     using System.Text;
     using System.Threading;
     using System.Threading.Tasks;
@@ -80,24 +81,44 @@ static async Task EdgeAgent(string managementUri)
 
         static async Task Iothub(string hostname, string port, string proxy)
         {
-            if (proxy != null)
+            if (port == "443")
             {
-                Uri proxyUri = new Uri(proxy);
-                IProxyClient proxyClient = MakeProxy(proxyUri);
+                var httpClientHandler = new HttpClientHandler();
 
-                // Setup timeouts
-                proxyClient.ReceiveTimeout = (int)TimeSpan.FromSeconds(60).TotalMilliseconds;
-                proxyClient.SendTimeout = (int)TimeSpan.FromSeconds(60).TotalMilliseconds;
+                if (proxy != null)
+                {
+                    Environment.SetEnvironmentVariable("https_proxy", proxy);
+                }
 
-                // Get TcpClient to futher work
-                var client = proxyClient.CreateConnection(hostname, int.Parse(port));
-                client.GetStream();
+                var httpClient = new HttpClient(httpClientHandler);
+                var logsUrl = string.Format("https://{0}/devices/0000/modules", hostname);
+                var httpRequest = new HttpRequestMessage(HttpMethod.Get, logsUrl);
+                HttpResponseMessage httpResponseMessage = await httpClient.SendAsync(httpRequest, HttpCompletionOption.ResponseHeadersRead);
             }
             else
             {
-                TcpClient client = new TcpClient();
-                await client.ConnectAsync(hostname, int.Parse(port));
-                client.GetStream();
+                // The current rust code never put proxy parameter when port is != than 443.
+                // So the code below is never exercised. It was put there to avoid silently ignoring the proxy
+                // if the rust code is changed.
+                if (proxy != null)
+                {
+                    Uri proxyUri = new Uri(proxy);
+                    IProxyClient proxyClient = MakeProxy(proxyUri);
+
+                    // Setup timeouts
+                    proxyClient.ReceiveTimeout = (int)TimeSpan.FromSeconds(60).TotalMilliseconds;
+                    proxyClient.SendTimeout = (int)TimeSpan.FromSeconds(60).TotalMilliseconds;
+
+                    // Get TcpClient to futher work
+                    var client = proxyClient.CreateConnection(hostname, int.Parse(port));
+                    client.GetStream();
+                }
+                else
+                {
+                    TcpClient client = new TcpClient();
+                    await client.ConnectAsync(hostname, int.Parse(port));
+                    client.GetStream();
+                }
             }
         }