BUG/MEDIUM: mux-quic: fix RESET_STREAM on send-only stream

BUG/MEDIUM: mux-quic: fix RESET_STREAM on send-only stream

When receiving a RESET_STREAM on a send-only stream, it is mandatory to
close the connection with an error STREAM_STATE error. However, this was
badly implemented as this caused two invocation of qcc_set_error() which
is forbidden by the mux-quic API.

To fix this, rely on qcc_get_qcs() to properly detect the error. Remove
qcc_set_error() usage from qcc_recv_reset_stream() instead.

This must be backported up to 2.7.