C#: Address CoPilots comments.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/EnvironmentVariableNames.cs

@@ -80,7 +80,7 @@ internal static class EnvironmentVariableNames
         public const string ProxyHost = "CODEQL_PROXY_HOST";
 
         /// <summary>
-        /// Specifies the hostname of the Registry proxy.
+        /// Specifies the port of the Registry proxy.
         /// </summary>
         public const string ProxyPort = "CODEQL_PROXY_PORT";