Log Message:
iperf3: updated to 3.8.1

iperf 3.8.1 2020-06-10
----------------------
* Notable user-visible changes
  * A regression with "make install", where the libiperf shared
    library files were not getting installed, has been fixed.

iperf 3.8 2020-06-08
--------------------
* Notable user-visible changes
  * Profiled libraries and binaries are no longer built by default.
  * A minimal Dockerfile has been added.
  * A bug with burst mode and unlimited rate has been fixed
  * Configuring with the --enable-static-bin flag will now cause
    a statically-linked iperf3 binary to be built.
  * Configuring with the --without-sctp flag will now prevent SCTP
    from being auto-detected.  This flag allows building a
    static binary (see above item) on a CentOS system with SCTP
    installed, because no static SCTP libraries are available.
  * Clock skew between the iperf3 client and server will no longer
    skew the computation of jitter during UDP tests.
  * A possible buffer overflow in the authentication feature has been
    fixed.  This was only relevant when configuration authentication
    using the libiperf3 API, and did not affect command-line usage.
    Various other improvements and fixes in this area were also made.

* Notable developer-visible changes
  * The embedded version of cJSON has been updated to 1.3.17.
  * Some server authentication functions have been added to the API.
  * API access has been added to the connection timeout parameter.
  * Tests for some authentication functions have been added.
  * Various compiler errors and warnings have been fixed.