[MacPorts] #55650: Update protobuf3-cpp to version 3.5.1

[MacPorts]

#55650: Update protobuf3-cpp to version 3.5.1
----------------------------------+----------------------
  Reporter:  MarcusCalhoun-Lopez  |      Owner:  blair@…
      Type:  update               |     Status:  closed
  Priority:  Normal               |  Milestone:
 Component:  ports                |    Version:
Resolution:  fixed                |   Keywords:  haspatch
      Port:  protobuf3-cpp        |
----------------------------------+----------------------

Comment (by kencu):

 That does work -- it shifts to pthreads instead of thread_local. I'm
 pondering any downsides to that, but don't see any...

 Every system should work. What do you think?

--
Ticket URL: <https://trac.macports.org/ticket/55650#comment:4>
MacPorts <https://www.macports.org/>
Ports system for macOS