PYBIND11_TLS_REPLACE_VALUE should use macro argument value in Python …

[jquesnelle]

The PYBIND11_TLS_REPLACE_VALUE macro doesn't actually use the value argument when using the new Python TLS API (3.7+). Instead, it always uses tstate as the argument. This works because the two places PYBIND11_TLS_REPLACE_VALUE is used in the code the argument is tstate.

1. pybind11/include/pybind11/pybind11.h

   Line 1890 in e2b884c

   PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate);

2. pybind11/include/pybind11/pybind11.h

   Line 1963 in e2b884c

   PYBIND11_TLS_REPLACE_VALUE(key, tstate);

However, for correctness, and for anyone piggybacking on pybind's cross-version TLS support (like me!) it should use the value argument

[wjakob]

Nice catch!