tests: Bring back check for old GnuTLS rehandshaking bug
tests: Bring back check for old GnuTLS rehandshaking bug

This reverts commit 2ef2af4ecd6bf06bc7000d7e13caf72a2eac7448.

Adapted to check for our new rehandshaking bug!

https://bugzilla.gnome.org/show_bug.cgi?id=794286

GNOME/glib-networking,GNOME/glib-networking,GNOME/glib-networking