Drop memory allocator from ClientNetworkGameSocketHandler

Have ClientNetworkGameSocketHandler initialise all of its members
on construction and not derive from ZeroedMemoryAllocator.

(cherry picked from commit dddda4f0b7ba0bd6f310f924d3b85cadbc81dc99)

src/network/network_client.cpp

@@ -123,7 +123,9 @@ struct PacketReader : LoadFilter {
  * Create a new socket for the client side of the game connection.
  * @param s The socket to connect with.
  */
-ClientNetworkGameSocketHandler::ClientNetworkGameSocketHandler(SOCKET s) : NetworkGameSocketHandler(s), savegame(NULL), status(STATUS_INACTIVE)
+ClientNetworkGameSocketHandler::ClientNetworkGameSocketHandler (SOCKET s)
+	: NetworkGameSocketHandler (s),
+	  savegame (NULL), token (0), status (STATUS_INACTIVE)
 {
 	assert(ClientNetworkGameSocketHandler::my_client == NULL);
 	ClientNetworkGameSocketHandler::my_client = this;

src/network/network_client.h

@@ -17,7 +17,7 @@
 #include "network_internal.h"
 
 /** Class for handling the client side of the game connection. */
-class ClientNetworkGameSocketHandler : public ZeroedMemoryAllocator, public NetworkGameSocketHandler {
+class ClientNetworkGameSocketHandler : public NetworkGameSocketHandler {
 private:
 	struct PacketReader *savegame; ///< Packet reader for reading the savegame.
 	byte token;                    ///< The token we need to send back to the server to prove we're the right client.