transport: don't lower the maximum throughput

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: increase aggregation timeout to 1 ms

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
message_multiplexer: don't check throughput

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>