reticulate 1.39 breaks embedding R in python environment.

[randy3k]

I am the author of radian, I was reported that radian doesn't work with new version of reticulate, see randy3k/radian#489.

After poking around, it seems that it is caused by this line

GILScope scope;

in main_process_python_info_unix. AFAICT, It is trying to initialize python by running reticulate:::initialize_python()
but initialize_python calls py_discover_config which calls main_process_python_info and main_process_python_info_unix.

It creates a dead loop.

I tried commented out this line // GILScope scope;, and it seems that it is now back in working, but not sure if GIL is needed in this function.