Replace NEKit dependency with reduced subset

GlassVPN/zhuhaow-NEKit/ProxyServer/GCDHTTPProxyServer.swift

@@ -0,0 +1,24 @@
+import Foundation
+
+/// The HTTP proxy server.
+public final class GCDHTTPProxyServer: GCDProxyServer {
+    /**
+     Create an instance of HTTP proxy server.
+
+     - parameter address: The address of proxy server.
+     - parameter port:    The port of proxy server.
+     */
+    override public init(address: IPAddress?, port: Port) {
+        super.init(address: address, port: port)
+    }
+
+    /**
+     Handle the new accepted socket as a HTTP proxy connection.
+
+     - parameter socket: The accepted socket.
+     */
+    override public func handleNewGCDSocket(_ socket: GCDTCPSocket) {
+        let proxySocket = HTTPProxySocket(socket: socket)
+        didAcceptNewSocket(proxySocket)
+    }
+}