pki: Fix accidental ECC switch case fallthroughs into ed25119 cases when built without ECC
When ed25519 was introduced in commit 93c7b81b4ea1046bd2f65f4a510d5966786e8d3d,
the ed25519 case was added after the ecdsa case in src/pki.c. The ecdsa case seems to
have relied on falling through to report an error, when HAVE_ECC is not defined.
If HAVE_ECC is not defined, but ecdsa keys are used, with for example,
ssh_pki_import_pubkey_file, the code fallthroughs into the ed25519 case.
Signed-off-by: Juraj Vijtiuk <firstname.lastname@example.org>
Test Plan: Unit tests passed. No memory leaks found with valgrind.
Differential Revision: https://bugs.libssh.org/D13
Reviewed-by: Andreas Schneider <email@example.com>