FT: Do not expose GTK/IGTK in FT Reassociation Response frame in OSEN

FT: Do not expose GTK/IGTK in FT Reassociation Response frame in OSEN

Do not include the actual GTK/IGTK value in FT protocol cases in OSEN or
with DGAF disabled (Hotspot 2.0). This was already the case for the
EAPOL-Key cases of providing GTK/IGTK, but the FT protocol case was
missed. OSEN cannot really use FT, so that part is not impacted, but it
would be possible to enable FT in a Hotspot 2.0 network that has DGAF
disabled.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>