third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/python/README.md

 Protocol Buffers - Google's data interchange format
 ===================================================
 
 [![Build Status](https://travis-ci.org/google/protobuf.svg?branch=master)](https://travis-ci.org/google/protobuf)
 
 Copyright 2008 Google Inc.
 
 This directory contains the Python Protocol Buffers runtime library.
 
 Normally, this directory comes as part of the protobuf package, available
@@ skipping 74 matching lines @@
      $ python setup.py test --cpp_implementation
 
    If some tests fail, this library may not work correctly on your
    system.  Continue at your own risk.
 
    Please note that there is a known problem with some versions of
    Python on Cygwin which causes the tests to fail after printing the
    error:  "sem_init: Resource temporarily unavailable".  This appears
    to be a bug either in Cygwin or in Python:
      http://www.cygwin.com/ml/cygwin/2005-07/msg01378.html
-   We do not know if or when it might me fixed.  We also do not know
+   We do not know if or when it might be fixed.  We also do not know
    how likely it is that this bug will affect users in practice.
 
 5) Install:
 
     $ python setup.py install
 
   or:
 
     $ (cd .. && make install)
     $ python setup.py install --cpp_implementation
@@ skipping 12 matching lines @@
   https://developers.google.com/protocol-buffers/
 
 C++ Implementation
 ==================
 
 The C++ implementation for Python messages is built as a Python extension to
 improve the overall protobuf Python performance.
 
 To use the C++ implementation, you need to install the C++ protobuf runtime
 library, please see instructions in the parent directory.