This is necessary to keep alignment between the client view of rig->state and the shared libarary view
Including PTHREAD functions in rig->state necessitated this as HAVE_PTHREAD only defined during hamlib compilation.
Clients including hamlib/rig.h did not pick up all the HAVE* config variable that control what gets included
https://github.com/Hamlib/Hamlib/issues/947
Mike Black W9MDB