When eap::config_method_eaphost::get_method_id() returns EAP-MSCHAPv2,
XML-to-BLOB gets confused and picks native EAP-MSCHAPv2 implementation.
Therefore, it was updated to always return unknown EAP type. Outer
method does not need to know the exact method implemented by EapHost
inner method.
Signed-off-by: Simon Rozman <simon@rozman.si>