Remove ecdsa ssh key type from supported list.
Rationale: Due to patent concerns, ECC support is not bundled in fedora/rhel(needed for ecdsa key generation).
           So even if someone has a valid ecdsa keys, sshd server on our node won't be able to authenticate the user.
Merge pull request #3111 from pravisankar/dev/ravi/bug983038

Merged by openshift-bot