ProtocolServer: Turn this into a multi-instance service

Everyone who connects to ProtocolServer now gets his own instance.
This means that different users can no longer talk to the same exact
ProtocolServer process, enhanching security and stability.

Base/etc/SystemServer.ini

@@ -2,10 +2,10 @@
 Socket=/tmp/portal/protocol
 SocketPermissions=660
 Lazy=1
-Priority=low
-KeepAlive=1
 User=protocol
 BootModes=text,graphical
+MultiInstance=1
+AcceptSocketConnections=1
 
 [WebContent]
 Socket=/tmp/portal/webcontent

Services/ProtocolServer/ClientConnection.cpp

@@ -48,6 +48,8 @@ ClientConnection::~ClientConnection()
 void ClientConnection::die()
 {
     s_connections.remove(client_id());
+    if (s_connections.is_empty())
+        Core::EventLoop::current().quit(0);
 }
 
 OwnPtr<Messages::ProtocolServer::IsSupportedProtocolResponse> ClientConnection::handle(const Messages::ProtocolServer::IsSupportedProtocol& message)

Services/ProtocolServer/main.cpp

@@ -56,18 +56,9 @@ int main(int, char**)
     (void)*new ProtocolServer::GeminiProtocol;
     (void)*new ProtocolServer::HttpProtocol;
     (void)*new ProtocolServer::HttpsProtocol;
-    auto server = Core::LocalServer::construct();
-    bool ok = server->take_over_from_system_server();
-    ASSERT(ok);
-    server->on_ready_to_accept = [&] {
-        auto client_socket = server->accept();
-        if (!client_socket) {
-            dbg() << "ProtocolServer: accept failed.";
-            return;
-        }
-        static int s_next_client_id = 0;
-        int client_id = ++s_next_client_id;
-        IPC::new_client_connection<ProtocolServer::ClientConnection>(*client_socket, client_id);
-    };
+
+    auto socket = Core::LocalSocket::take_over_accepted_socket_from_system_server();
+    ASSERT(socket);
+    IPC::new_client_connection<ProtocolServer::ClientConnection>(socket.release_nonnull(), 1);
     return event_loop.exec();
 }