NPN was removed from NSS a long time ago, this effectively does nothing.
ALPN also should be default-enabled (we do this by pref but the component
itself should have a sane default) so this was flipped as a drive-by fix.
Resolves#2723
Apparently a prehistoric server implementation would send a certificate_authorities field
that didn't include the outer DER SEQUENCE tag, so PSM attempted to detect this and
work around it.
This prehistoric server implementation isn't in use anywhere anymore, so this 18-yo
server bug workaround can be removed.
This creates a number of stubs and leaves some surrounding code that may be irrelevant (eg. recorded time stamps, status variables).
Stub resolution/removal should be a follow-up to this.
