Avoid sending packets in an unacknowledged window

Cherry picked from upstream

Source/Native/enet.h

@@ -2775,7 +2775,7 @@ static int enet_protocol_check_outgoing_commands(ENetHost* host, ENetPeer* peer)
 			reliableWindow = outgoingCommand->reliableSequenceNumber / ENET_PEER_RELIABLE_WINDOW_SIZE;
 
 			if (channel != NULL) {
-				if (!windowWrap && outgoingCommand->sendAttempts < 1 && !(outgoingCommand->reliableSequenceNumber % ENET_PEER_RELIABLE_WINDOW_SIZE) && (channel->reliableWindows[(reliableWindow + ENET_PEER_RELIABLE_WINDOWS - 1) % ENET_PEER_RELIABLE_WINDOWS] >= ENET_PEER_RELIABLE_WINDOW_SIZE || channel->usedReliableWindows & ((((1 << (ENET_PEER_FREE_RELIABLE_WINDOWS + 1)) - 1) << reliableWindow) | (((1 << (ENET_PEER_FREE_RELIABLE_WINDOWS + 1)) - 1) >> (ENET_PEER_RELIABLE_WINDOWS - reliableWindow)))))
+				if (!windowWrap && outgoingCommand->sendAttempts < 1 && !(outgoingCommand->reliableSequenceNumber % ENET_PEER_RELIABLE_WINDOW_SIZE) && (channel->reliableWindows[(reliableWindow + ENET_PEER_RELIABLE_WINDOWS - 1) % ENET_PEER_RELIABLE_WINDOWS] >= ENET_PEER_RELIABLE_WINDOW_SIZE || channel->usedReliableWindows & ((((1 << (ENET_PEER_FREE_RELIABLE_WINDOWS + 2)) - 1) << reliableWindow) | (((1 << (ENET_PEER_FREE_RELIABLE_WINDOWS + 2)) - 1) >> (ENET_PEER_RELIABLE_WINDOWS - reliableWindow)))))
 					windowWrap = 1;
 
 				if (windowWrap) {