Follow-up from "Draft: sctp: bundle usrsctp"

The following discussion from !1465 (merged) should be addressed:

• @tpm started a discussion: (+5 comments)

  valgrind -bad datachannel/webrtc tests are not happy, so something's probably not quite right

• test_data_channel_remote_notify

• test_data_channel_pre_negotiated

• test_data_channel_low_threshold

• test_data_channel_transfer_data

• test_data_channel_transfer_string

• test_data_channel_create_after_negotiate

• test_data_channel_max_message_size

• test_renego_data_channel_add_stream

valgrind logs: leaks.log