Used the non-blocking recv function, to ensure that the game doesn't hang if the server doesn't respond.

check_input.cpp

@@ -62,14 +62,13 @@ GameType check_client(char* code_text) {
 		client->create_socket();
 		/* Send a specific message to the server, and wait for the appropriate response, to know that the server is ready */
 		client->sendAll("GG");
-//		display_text_centered("Connecting...");
-		std::string msg_from_server = client->recvAll();
+		std::string msg_from_server = client->recvAllNB();
 		if (msg_from_server == "U2") {
 			display_text_centered("Connection made");
 			Timer timer = timer_init(3);
 			while (!timer_done(timer));
 		} else {
-			throw EXCEPT_WRONGRESPONSE;
+			throw std::invalid_argument("Server didn't respond with correct message.");
 		}
 		type.mode = M_CLIENT;
 		type.netsock = client;