fixing indentation in pseudocode

Co-authored-by: Junho Choi <1229714+junhochoi@users.noreply.github.com>

draft-ietf-quic-recovery.md

@@ -1534,7 +1534,7 @@ newly acked_packets from sent_packets.
 
     // Do not increase congestion window in recovery period.
     if (InCongestionRecovery(acked_packet.time_sent)):
-        return
+      return
 
     if (congestion_window < ssthresh):
         // Slow start.