wpa: Enable WEP by default

As of hostap 2.10, WEP is disabled by default. This of course is not a
bad thing but requires some planning and an announcment to remove WEP
support by default. A possible src.conf knob or letting users know they
should use the port instead might different options.

(cherry picked from commit 7999a7f2a8679f73574b6704377436025601ee85)