It is not possible to use a single data stream

[duncanmcl]

In the Quic code base at https://github.com/signetlabdei/quic, the default number of data streams is set to 2. I saw two problems:

1. The parameters MaxStreamIdBidi and MaxStreamIdUni can change the number of streams, but they are not used in the examples. People may not notice that they are simulating with two streams, so it may be better to set the default number streams to 1.

2. I tried to change the number of data streams to 1 in my simulation script by setting the parameters MaxStreamIdBidi and MaxStreamIdUni to 1. However, the simulation crashed with error "died with <Signals.SIGFPE: 8>".

I did debugging and saw that the line "if (m_streams.size() != m_socket->GetMaxStreamId()) {" in quic-l5-protocol.cc should be "if (m_streams.size()-1 != m_socket->GetMaxStreamId()) {"