tests: Generating large-enough DSA keys works in FIPS mode

The a93d678f previously added this condition, but the DSA key size
changed since then to 2k, which is still allowed.

• tests/pubkey.c (get_dsa_key_with_domain_new): DSA keys still work in FIPS mode. --

• Signed-off-by: Jakub Jelen <jjelen@redhat.com>