Fix breaking change in symbol server

Author: waf

CSharpRepl.Services/Configuration.cs

@@ -40,7 +40,7 @@ public sealed class Configuration
     public static readonly IReadOnlyCollection<string> SymbolServers =
     [
         "https://symbols.nuget.org/download/symbols/",
-        "http://msdl.microsoft.com/download/symbols/"
+        "https://msdl.microsoft.com/download/symbols/"
     ];
 
     public HashSet<string> References { get; }

CSharpRepl.Services/SymbolExploration/DebugSymbolLoader.cs

@@ -52,7 +52,7 @@ private CacheSymbolStore BuildSymbolStore()
 
         foreach (var server in Configuration.SymbolServers)
         {
-            store = new HttpSymbolStore(logger, store, new Uri(server), null);
+            store = new HttpSymbolStore(logger, store, new Uri(server), accessToken: null);
         }
 
         var cacheDirectory = Path.Combine(Configuration.ApplicationDirectory, "symbols");

CSharpRepl.Services/SymbolExploration/SymbolExplorer.cs

@@ -84,6 +84,11 @@ public async Task<SymbolResult> LookupSymbolAtPosition(string text, int position
 
         foreach (var key in debugSymbolLoader.GetSymbolFileNames()) // we'll choose the first pdb we can successfully load. This will skip over e.g. Windows pdb files.
         {
+            if (key.FullPathName.Contains(".ni.pdb"))
+            {
+                continue;
+            }
+
             using SymbolStoreFile symbolFile = await debugSymbolLoader.DownloadSymbolFile(key, CancellationToken.None);
 
             var symbolReader = debugSymbolLoader.ReadPortablePdb(symbolFile);