Description of problem:
When the server uses an ECDSA key, curl fails to verify it's entry in the known hosts file when accessing using SFTP.

Version-Release number of selected component (if applicable):
curl-7.69.1-1.f32

How reproducible:
100%

Steps to Reproduce:

1. Create an ECDSA key pair for the SSH server:

# ssh-keygen -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key -N ''

2. Authorize the user key to access the SSH server (assuming the user has an RSA key):

$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

3. Add the entry to the known_hosts file

$ echo 'localhost $(cat "/etc/ssh/ssh_host_ecdsa_key.pub")' >> ~/.ssh/known_hosts

4. Create a file to download:

$ dd if=/dev/zero of=~/testfile bs=1M count=1

5. Restart SSH server

$ systemctl restart sshd

6. Download using curl and SFTP

$ curl -o ./sftp_file -u testuser: --key ~/.ssh/id_rsa \
  --pubkey ~/.ssh/id_rsa.pub sftp://localhost/home/$(whoami)/testfile

Actual results:
curl: (60) SSL peer certificate or SSH remote key was not OK

Expected results:
No errors and the file is downloaded correctly.

Additional info:
Using RSA, ED25519, or DSA keys no error is generated and the download is successful