Fix security/easy-rsa regression that broke bootstrapping.

v3.0.5 added code that expanded variables, for compatibility with LibreSSL.
This code assumed that the source configuration file could be variable-
expanded and the result could be saved next to the source - which it
cannot, since the latter is under ${PREFIX} where the unprivileged users
should not be able to write.

Add a patch provided by Eric Crist, and rename another file to keep
a sane patch order.