GnuTLS docs are not clear about thread-safety of intialization ?
From https://curl.haxx.se/mail/lib-2020-01/0021.html
For GnuTLS 3.3.0 and later I *suspect* it inits itself in a thread-safe
manner. Their docs isn't very clear on this subject:
https://gnutls.org/manual/html_node/Initialization.html#Initialization
We should check the docs...