build: Remove dependencies to libgthread - TRIVIAL
libgthread was needed to call g_thread_init. This was removed by this commit:
commit 3e116a6c71b77d04260877778f8553cc4aec2ec5
Date: Wed Feb 6 13:32:09 2019 +0000
Obsolete Glib cleanup
We require at least GLib 2.38, remove code and check to
support earlier versions.
Signed-off-by: Frediano Ziglio freddy77@gmail.com