message: Refresh ZeroMQ 4.3.1 patch
  Some patch implementations can't handle fuzz / too much divergence from the
  original code.
  This just tweaks the context code around the patch so that less-sophisticated
  patch implementations (such as on Alpine Linux) can apply the patch without
  errors.
diff: @@ -12,7 +12,7 @@ diff --git a/src/thread.cpp b/src/thread.cpp
  index a1086b0c..9943f354 100644
  --- a/src/thread.cpp
  +++ b/src/thread.cpp
  -@@ -307,7 +307,7 @@ void zmq::thread_t::setThreadName (const char *name_)
  +@@ -308,7 +308,7 @@ void zmq::thread_t::setThreadName (const char *name_)
  */
  if (!name_)
  return;
  @@ -21,9 +21,9 @@ index a1086b0c..9943f354 100644
  #if defined(ZMQ_HAVE_PTHREAD_SETNAME_1)
  int rc = pthread_setname_np (name_);
  if (rc)
  -@@ -323,6 +323,8 @@ void zmq::thread_t::setThreadName (const char *name_)
  +@@ -324,6 +324,8 @@ void zmq::thread_t::setThreadName (const char *name_)
  #elif defined(ZMQ_HAVE_PTHREAD_SET_NAME)
  - pthread_set_name_np (descriptor, name_);
  + pthread_set_name_np (_descriptor, name_);
  #endif
  +#endif
  + return;
  