Allow TSN AP to be selected when configured for WEP

Allow TSN AP to be selected when configured for WEP

Commit d8d940b7469e505aec4d71a02d3f7ebab412eeae introduced a regression
that prevented TSN APs from being used with WEP since the AP was
rejected if it advertised WPA or RSN IE when we were configured to use
WEP. Resolve this by checking whether the AP is advertising a TSN, i.e.,
whether the AP allows WEP to be used as a group cipher. If so, allow
the AP to be selected if we are configured to use static WEP or
IEEE 802.1X (non-WPA).

It should be noted that this is still somewhat more restricted in AP
selection than earlier wpa_supplicant branches (0.7.x or older) that
ignore the WPA/RSN IE completely when configured for non-WPA.