Reformat evptests.txt

When compiling without EC support the test fails abruptly reading some keys.
Some keys merged in commit db04055 start with
------BEGIN EC PRIVATE KEY-----

this format is not supported without EC support.

This commit reformat those keys with the generic format. After this change the
test simply skips the unsupported EC keys when EC is disabled, without parsing
errors.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3223)